Synergistic effect of potential alpha-amylase inhibitors from Egyptian propolis with acarbose using in silico and in vitro combination analysis.

BACKGROUND: Type 2 Diabetes mellitus (DM) is an affliction impacting the quality of life of millions of people worldwide. An approach used in the management of Type 2 DM involves the use of the carbohydrate-hydrolyzing enzyme inhibitor, acarbose. Although acarbose has long been the go-to drug in this key approach, it has become apparent that its side effects negatively impact patient adherence and subsequently, therapeutic outcomes. Similar to acarbose in its mechanism of action, bee propolis, a unique natural adhesive biomass consisting of biologically active metabolites, has been found to have antidiabetic potential through its inhibition of α-amylase. To minimize the need for ultimately novel agents while simultaneously aiming to decrease the side effects of acarbose and enhance its efficacy, combination drug therapy has become a promising pharmacotherapeutic strategy and a focal point of this study. METHODS: Computer-aided molecular docking and molecular dynamics (MD) simulations accompanied by in vitro testing were used to mine novel, pharmacologically active chemical entities from Egyptian propolis to combat Type 2 DM. Glide docking was utilized for a structure-based virtual screening of the largest in-house library of Egyptian propolis metabolites gathered from literature, in addition to GC-MS analysis of the propolis sample under investigation. Thereafter, combination analysis by means of fixed-ratio combinations of acarbose with propolis and the top chosen propolis-derived phytoligand was implemented. RESULTS: Aucubin, identified for the first time in propolis worldwide and kaempferol were the most promising virtual hits. Subsequent in vitro α-amylase inhibitory assay demonstrated the ability of these hits to significantly inhibit the enzyme in a dose-dependent manner with an IC50 of 2.37 ± 0.02 mM and 4.84 ± 0.14 mM, respectively. The binary combination of acarbose with each of propolis and kaempferol displayed maximal synergy at lower effect levels. Molecular docking and MD simulations revealed a cooperative binding mode between kaempferol and acarbose within the active site. CONCLUSION: The suggested strategy seems imperative to ensure a steady supply of new therapeutic entities sourced from Egyptian propolis to regress the development of DM. Further pharmacological in vivo investigations are required to confirm the potent antidiabetic potential of the studied combination.

Chitosan Schiff base electrospun fabrication and molecular docking assessment for nonleaching antibacterial nanocomposite production.

In this work, new chitosan derivative nanofibers that exhibit antibacterial properties were successfully fabricated. The two CS Schiff base derivatives (CS-APC and CS-2APC) were prepared by incorporating 4-amino antipyrine moiety in two different ratios, followed by a reductive amination to obtain the corresponding derivatives CS-APCR and CS-2APCR. Spectral analyses were used to confirm the chemical structure. The molecular docking evaluation of CS-APC, CS-APCR, and CS was conducted on DNA topoisomerase IV, thymidylate kinase and SARS-CoV-2 main protease (3CLpro) active sites. CS-APCR showed a well-fitting into the three enzyme active sites with docking score values of - 32.76, - 35.43 and - 30.12 kcal/mol, respectively. The nanocomposites of CS derivatives were obtained by electrospinning the blends of CS-2APC and CS-2APCR with polyvinyl pyrrolidone (PVP) at 20 kV. The morphology of the nanofibers was investigated by scanning electron microscopy (SEM). It was found that fiber diameters were significantly decreased when CS-2APC and CS-2APCR were incorporated into pure PVP to reach 206-296 nm and 146-170 nm, respectively, compared to 224-332 nm for pure PVP. The derivatives of CS and their nanofibers with PVP were found to have antibacterial activities against two strains of Staphylococcus aureus and Escherichia coli. Data revealed that CS-2APC nanofibers showed antibacterial activity to the two strains of E. coli less than CS-2APCR nanofibers.

Self-stick membrane based on grafted gum Arabic as active food packaging for cheese using cinnamon extract.

Encapsulation of volatile essential oils has been investigated to provide an active food packaging (AFP) material with more control over their fast release and pungent smell. In this work, Gum Arabic-based adhesive membrane was developed as a self-stick AFP material, delivering cinnamon essential oil (CEO) in vapor phase. Gum Arabic (GA) was grafted with butyl acrylate (BA) and hydroxyethyl methacrylate [GA-g-poly(BA-HEMA)]. Adhesive membrane was characterized by means of spectral, physicochemical and rheological analysis. GA-adhesive membrane made of 5% wt/v GA, 3.5 m mol HEMA, and 87 m mol BA with 21 N/m tack are loaded with 4, 8 and 10% v/v of CEO and used for antimicrobial bioassays. GA-g-poly(BA-HEMA) membrane prolonged CEO release up to 2 days. 8%v/v CEO showed superior activities against both Gram negative and positive bacteria. Shelf-life of cheese samples, packed with the self-stick membranes loaded with cinnamon extract, has extended from 3 to 8 weeks. Cheese samples that inoculated with shiga toxin producing E. coli O157:H7 and packed in plastic boxes with the self-stick AFP (4, 8 and 10 % CEO), showed significant reduction in the total bacteria counts.

Hydrogel bioink based on clickable cellulose derivatives: Synthesis, characterization and in vitro assessment.

Hydrogel is considered as a promising candidate for bioink in terms of biocompatibility, biodegradability, printability and supporting cellular behavior. Recently, carbohydrates derivatives containing alkyne and azide pendant functional groups have been used in medical applications due to their improved chemical, biological, functional properties, and their amenability for chemical reactions under mild conditions. In this work, a novel bioink was developed based on azide and alkyne of cellulose derivatives. Azido-hydroxyethyl cellulose (D.Sazido = 0.04) was synthesized via open-ring reaction of 1-azido-2,3-epoxypropane and characterized spectroscopically and titrimetrically. Alkyne derivative, propargyl carboxymethyl cellulose (D.Spropargyl = 1.72) was synthesized through coupling reaction with propargylamine in the presence of EDC and NHS. The click-gel scaffold was obtained by mixing the two novel candidates in the presence of copper (I) catalyst. Extrusion bio-plotting experiment was successfully conducted of the two solutions into coagulant Cu (I)/DMSO solutions and demonstrated the possibility of using the clickable cellulose derivatives as bioink precursors. Chemical and physical properties of the click-gel were demonstrated. The biocompatibility assay of the prepared click-gels showed high level of viability in the human skin fibroblast cells (HFB4) at concentration 100 µg/mL.

Multi-layer dressing made of laminated electrospun nanowebs and cellulose-based adhesive for comprehensive wound care.

In this work, multi-layer wound dressing was made of laminated layers of electrospun fibers supported by adhesive sheet. Graft copolymerization of methyl methacrylate (MMA) and 2-Ethyl-1-hexyl acrylate (EHA) onto carboxymethyl cellulose (CMC) was conducted to obtain an adhesive sheet with 1.52 (N/cm2) loop tack, 1.7 (N/cm) peel strength and 25 s shear strength. Diclofenac sodium, anti-inflammatory drug, was loaded to the adhesive sheet with encapsulation efficiency 73%. The contact layer to wound was made of synthesized anti-bleeding agents, chitosan iodoacetamide (CI) loaded into electrospun polyvinyl alcohol (PVA) fibers. It was fabricated from fiber diameter 300 nm by electrospinning of 5% wt/v of CI (D.S. 18.7%) mixed with 10% wt/v PVA, at 20 kV and 17 cm airgap. The second, pain-relief layer was fabricated by encapsulating up to 50% wt/wt of capsaicin into gelatin nanofibers (197 nm) crosslinked by glyoxal. The third, antimicrobial layer was fabricated from PVA electrospun fibers loaded with 2% wt/wt gentamicin. Biocompatibility test showed insignificant adverse effects of the fabricated layers on fibroblast cells. Animal test on rat showed accelerated wound healing from 21 to 7 days for the multi-layer dressing. Histopathological findings corroborated the intactness of the epidermis layer of the treated samples.

Fabrication of cellulose-based adhesive composite as an active packaging material to extend the shelf life of cheese.

Traditional solutions of food packing are limited for antimicrobial packaging materials that interact with the product to inhibit the growth of microorganisms. In this work, adhesive composite was developed as an active packaging material using allyl isothiocyanate (AIC) in vapor phase. Such adhesive composite was made of gelatin electrospun fibers loaded by AIC and supportive adhesive sheet. Gelatin electrospun fibers loaded by AIC (2-10% v/v) into 24% wt/v gelatin solutions was produced using electrospinning apparatus at 15 kV, 15 cm air gap and 0.2 mL/h flow rate. This mat was supported by pressure-sensitive adhesive (PSA) made of hydroxyethyl cellulose backbone grafted by acrylic acid and methylbutyl acrylate [HEC-g-poly(AA-MBA)]. PSA was characterized in means of spectral, physicochemical and rheological analysis. Final product with AIC (2% v/v) showed significant antimicrobial activities against two food born bacteria including Staphylococcus aureus ATCC 25923 and Escherichia coli O157:H7. Antimicrobial activities on cheese showed that gelatin nanofibers loaded by AIC (10% v/v), applied in the headspace, extended the shelf life of cheese from 4 weeks to 8 weeks.

Fabrication of nanofiltration membrane based on non-biofouling PVP/lecithin nanofibers reinforced with microcrystalline cellulose via needle and needle-less electrospinning techniques.

In this work, polyvinylpyrrolidone nanofibers were electrospun incorporated with lecithin, zero-charge natural segment, as non-biofouling nanofiltration membrane with tunable porous structures. Optimum conditions were studied to obtain nano-pore size capable of nano-scaled objects reduction using needle and needleless electrospinning apparatuses. Fiber diameters were in proportional relationship with PVP concentrations to range from 1.2 um to 34 nm at 10 to 5% wt/v PVP respectively. Microcrystalline cellulose (MCC) was added and PVP fibers were photo-crosslinked to enhance the mechanical strength. Mechanical properties of electrospun fibers were enforced up to 279% in the presence of microcrystalline cellulose while increased by 125% when exposed to photo-crosslinking for 8 h by UV-light radiation. UV-crosslinking has significantly improved the hydrophobicity of the final mat to report contact angle bigger than 90° at 16 h. Protein adhesion test was conducted to indicate the capability of the electrospun membrane to bypass the blood-plasma products. Zero protein adhesion was recorded by adding only 2% wt/v of lecithin.

Potential role of medicinal plants and their constituents in the mitigation of SARS-CoV-2: identifying related therapeutic targets using network pharmacology and molecular docking analyses.

Since the outbreak of Coronavirus disease (COVID-19) caused by SARS-CoV-2 in December 2019, there has been no vaccine or specific antiviral medication for treatment of the infection where supportive care and prevention of complications is the current management strategy. In this work, the potential use of medicinal plants and more than 16 500 of their constituents was investigated within two suggested therapeutic strategies in the fight against SARS-CoV-2 including prevention of SARS-CoV-2 RNA synthesis and replication, through targeting vital proteins and enzymes as well as modulation of the host's immunity through production of virulence factors. Molecular docking studies on the viral enzymes 3Clpro, PLpro and RdRp suggested rocymosin B, verbascoside, rutin, caftaric acid, luteolin 7-rutinoside, fenugreekine and cyanidin 3-(6''-malonylglucoside) as promising molecules for further drug development. Meanwhile, the medicinal plants Glycyrrhiza glabra, Hibiscus sabdariffa, Cichorium intybus, Chrysanthemum coronarium, Nigella sativa, Anastatica hierochuntica, Euphorbia species, Psidium guajava and Epilobium hirsutum were enriched in compounds with the multi-targets PTGS2, IL2, IL1b, VCAM1 and TNF such as quercetin, ursolic acid, kaempferol, isorhamnetin, luteolin, glycerrhizin and apigenin. Enriched pathways of the molecular targets included cytokine-cytokine receptor interaction, TNF signaling pathway, NOD-like receptor signaling pathway, Toll-like receptor signaling pathway, NF-kappa B signaling pathway and JAK-STAT3 signaling pathway which are all closely related to inflammatory, innate and adaptive immune responses. The present study identified natural compounds targeting SARS-CoV-2 for further in vitro and in vivo studies and emphasizes the potential role of medicinal plants in the mitigation of SARS-CoV-2.

Soft hydrogel based on modified chitosan containing P. granatum peel extract and its nano-forms: Multiparticulate study on chronic wounds treatment.

Punica granatum peel (PGP) is widely used in traditional medicinal purposes for chronic wounds owing to containing natural phenolics active components. In current study, active wound dressing hydrogel for chronic wound healing was prepared based on P. granatum peel crude extract (PGPC), ethyl acetate fraction (PGPEA) and their silver nanoforms (Ag-NPs). Methacrylated chitosan was synthesized as precursor to hydrogel and crosslinked by divinyl sulfone (DVS) in mild condition. Hydrogel was fully characterized by spectral morphological, mechanical and physical analyses. The integration of PGPEA silver nanoforms was formed with particle size of 15-56 nm to show minimum inhibitory concentration (MIC) equal 63 for Staphylococcus aureus and 125 for Pseudomonas aeruginosa. The hydrogel-based wound dressing with/without the active ingredients showed acceptable cytotoxicity against fibroblast human cells for PGPC and PGPEA fraction over the silver nanoforms. Rat as animal model was considered to show the impact of the active wound dressing on diabetic wounds which was proved by histopathological examination. In addition, the significant intensity of immunopositivity signals of the transforming growth factor beta (TGF-ß1) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in the epidermal cells have revealed the efficiency of Ag NPs-PGPEA-chitosan hydrogel for chronic wound curing.

The synthesis and characterization of zinc-containing electrospun chitosan/gelatin derivatives with antibacterial properties.

Homogenous allocation of inorganic particles in a polymeric matrix is a challenge. In this work, we discuss electrospinning of chitosan /gelatin using CS-Si (chitosan silicone hybrids) as well as the formation of homogeneously distributed Zn elements inside chitosan nanofiber through chitosan -GPTMS hybrids. Chitosan -GPTMS hybrids can be synthesized by acid catalyzed amino-oxirane addition reaction. The proposed mechanism was approved by using spectral and elemental analyses. The chitosan derivative Si-Cs was mixed with gelatin and their solution were applied to electrospinning. Optimization of spinning process is reached. A homogeneous spinnable solution with desirable properties is obtained by addition of Zinc acetate. The characterizations of the spinnable solution in term of electrical conductivity and viscosity were studied. Characterization of the nanofiber formed by SEM show that there is no Zn accumulated on the nanofiber surfaces which is one of the advantages of introducing GPTMS to Cs chain. The superior antibacterial activity of the produced zinc-containing electrospun fibers of Gelatin-Si-Cs nominate it to be applied for medical purpose.

Biocompatible chitosan-based hydrogel with tunable mechanical and physical properties formed at body temperature.

Chemical crosslinking hydrogels provide irreversible matrices with reliable characteristics for wider medical applications. When hydrogels used for hosting bioactive substances, matrices have to be crosslinked at mild condition with high yield reaction and inactive to the biological molecules. In this work, chitosan was functionalized with active double bonds as a precursor to hydrogel that gels at body temperature. Free-radical crosslinking was conducted in the presence of maleic anhydride (MA) and potassium persulfate (KPS). The chemical structures of hydrogels were confirmed via spectral analysis. Mechanical and gelation characteristics of the hydrogels were tuned by using different molar ratios of MA and KPS. Pores size was controlled according to the crosslinking density in range of 313-866 µm that agrees proportionally with the swelling degree. Young's modulus values were tuned to span from 6 to 31 Pa with opposite relationship with the stress at break that varied from 6 to 17 Pa. Hydrogel release profiles were plotted representing varied releasing rates. Gels were obtained at 37 °C for 2 h using KPS (24-48 mM) and different concentration of MA (0.17, 0.35 and 0.5 M). The tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide (MTT), colorimetric, biological assay using skin fibroblast cells showed high biocompatibility of chitosan-based hydrogels.

Cellulose-based click-scaffolds: Synthesis, characterization and biofabrications.

Carbohydrates derivatives containing propargyl pending functional groups have been used in medical applications due to their improved chemical, biological, and functional properties. In this work, azide and alkyne pendant functional groups were introduced onto ethyl cellulose (EC) and ß-cyclodextrin respectively in order to demonstrate the ability of scaffold formation by click chemistry. Technically, Azido-ethyl cellulose (D.S.Azido 0.19) and 2, 3, 6-O- propargylated ß -cyclodextrin were synthesized and characterized as click-triggered candidates. The click-gel scaffold was obtained by mixing the two novel candidates in the presence of copper catalyst. Azido-EC was considered to produce clickable electrospun fibers blended with EC (290-620 nm) at 20 kV in order to functionalized EC substrate bearing azide groups to be amenable towards immobilization of an alkyne-terminated bio-molecules. The biocompatibility assay of the prepared click-triggered candidates showed very high level of viability in the human skin fibroblast cells (HFB4) at concentration 100 µg/ml.

Superabsorbent hydrogel based on sulfonated-starch for improving water and saline absorbency.

The agriculture sectors in many developing countries have been suffering from water shortage and decreasing crop yields. Thus, an increasing interest has been emerged to develop much-needed solutions for a more sustainable management of water resources. Agricultural hydrogel that absorbs many times of its weight in water has been used to distribute into dry regions in order to improve the soil's ability to absorb and retain water. Here, amphoteric superabsorbent hydrogel is prepared by indirect method based on anionic starch bearing sulfonate groups. Anionic starch derivatives were graft-polymerized with acrylonitrile (AN) and hydrolyzed by alkaline by which nitrile groups were converted to hydrophilic functional groups. The hydrolyzed sodium starch sulfate-g-polyacrylonitrile (HSSS-g-PAN) copolymer exhibited improved water and saline absorbencies compared to that of native starch-based hydrogel. The co-polymerization was conducted for 60min polymerization time, 0.75% (wt/wt) ammonium persulfate (APS) associated with sodium bisulfite, SBS, (50% (wt/wt) of APS), 65°C for polymerization temperature and double molar ratio of acrylonitrile to the starch derivatives. The hydrogel based on the sulfonated starch derivatives 1 and 2 showed superior water absorbency for both distilled (250% and 190% respectively) and saline (90% and 70%) solutions over that of the native starch.

Bioactive polymeric formulations for wound healing.

Ricinoleic acid (RA) has potential to promote wound healing because of its analgesic and anti-inflammatory properties. This study investigates the synthesis and characterization of RA liposomes infused in a hydrogel for topical application. Lecithin liposomes containing RA were prepared and incorporated into a chitosan solution and were subsequently cross-linked with dialdehyde ß-cyclodextrin (Di-ß-CD). Chitosan/Di-ß-CD concentrations and reaction temperatures were varied to alter gelation time, water content, and mechanical properties of the hydrogel in an effort to obtain a wide range of RA release profiles. Hydrogel cross-linking was confirmed by spectroscopy, and liposome and carrier hydrogel morphology via microscopy. Chitosan, Di-ß-CD, and liposome concentrations within the formulation affected the extent of matrix swelling, mechanical strength, and pore and overall morphology. Higher cross-linking density of the hydrogel led to lower water uptake and slower release rate of RA. Optimized formulations resulted in a burst release of RA followed by a steady release pattern accounting for 80% of the encapsulated RA over a period of 48 hours. However, RA concentrations above 0.1 mg/mL were found to be cytotoxic to fibroblast cultures in vitro because of the oily nature of RA. These formulations promoted wound healing when used to treat full thickness skin wounds (2 cm2) in Wister male rats. The wound contraction rates were significantly higher compared to a commercially available topical cream after a time period of 21 days. Histopathological analysis of the RA-liposomal chitosan hydrogel group showed that the epidermis, dermis, and subcutaneous skin layers displayed an accelerated yet normal healing compared to control group.

Technique and outcome of autotransplanting thyroid tissue after total thyroidectomy for simple multinodular goiters.

BACKGROUND/OBJECTIVE: Limited animal and human studies have shown function, albeit inadequate, of implanted thyroid tissue in muscles. This work aimed to ascertain results in a larger number of patients, finding practical method for implantation, studying the effect of changing weight of implant and effect of passage of time on its function. METHODS: Forty patients had total thyroidectomy for simple multinodular goiters. A piece of the excised gland was finely minced, mixed with saline as emulsion, and injected in thigh muscles. Twelve patients had 5-g implants, while 28 patients had 10-g implants. Four parameters were studied at 2 months, 6 months, and 12 months: technetium isotope uptake by the implant; thyroid stimulating hormone (TSH); free T3 (FT3); and free T4 (FT4). RESULTS: All autotransplanted thyroid tissue survived and functioned. After 12 months, mean values (± standard deviation) of isotope uptake, TSH, FT3, and FT4 of the 5-g implants were 0.44 ± 0.16%, 27.74 ± 30.4 UI/mL, 3.07 ± 1.10 pg/mL, and 1.01 ± 0.3 ng/dL, repectively. Those for the 10 g implants were 0.71 ± 0.20%, 22.78 ± 19.7 UI/mL, 3.92 ± 1.2 pg/mL, and 1.05 ± 0.3 ng/dL, repectively. Ten-gram implants showed significantly higher isotope uptake than 5-g. TSH, FT3, and FT4 significantly improved over the period of 1 year. CONCLUSION: Injection of thyroid tissue suspension is a simple method for thyroid autotransplantation. TSH was elevated in the majority to maintain normal or near normal thyroid hormones. Ten-gram implants showed higher isotope uptake than 5-g, although this difference was not reflected by thyroid hormone profile. The implant seemed to function better with the passage of time from 2 months to 12 months.

Impregnation of silver nanoparticles into polysaccharide substrates and their properties.

A method to impregnate silver nanoparticles (AgNPs) into different polysaccharides substrates (cellulose powder (CP), microcrystalline cellulose (MCC), carboxymethyl cellulose (CMC) and chitosan (Chit)) by using glucose as reducing agent, is presented. X-ray diffraction analyses of polysaccharides coated with AgNPs showed the formation of silver particle sizes in the range of 3.7-5.6 nm and have almost spherical shape. The entire prepared composite shows antimicrobial effect. The antibacterial activity of polysaccharides loaded with silver nanoparticles was evaluated against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria. The results suggest excellent antibacterial activity.