Wound dressing membranes based on immobilized Anisaldehyde onto (chitosan-GA-gelatin) copolymer: In-vitro and in-vivo evaluations.

Herein, wound dressing membranes based on covalently linked Chitosan (Ch) to Gelatin (GE) via Glutaraldehyde (GA) to have (Ch-GA-GE) copolymer have been developed. In addition, Anisaldehyde (An) was immobilized onto Ch-GA-GE to has An-(Ch-GA-GE) membrane. The changes of the Ch-GA-GE membranes wettability, from 26 ± 1.3° to 45.3 ± 2.27° of the An-(Ch-GA-GE) copolymer membrane, indicating the reduction of copolymers hydrophilicity. The thermal characterization was done using TGA and DSC, while the morphological analysis was done using SEM. The antibacterial properties were assessed against four bacterial strains (P. aeruginosa, S. aureus, Streptococcus, and E. coli). In-vitro evaluation of the fabricated membranes to be used as wound dressings was investigated by measuring their hemocompatibility, cytotoxicity, and biodegradability. Finally, the in-vivo assessment of the developed membranes to encourage skin regeneration was assessed utilizing adult Wistar albino rats. The results illustrated that the An-(Ch-GA-GE) copolymer membranes significantly enhanced the rat's full-thickness injuries, as monitored by reducing the wound region. Furthermore, histological analyses of the injuries covered with An-(Ch-GA-GE) membranes demonstrated a notable re-epithelialisation contrasted with wounds treated with the cotton gauze Ch-GA-GE membranes dressings proving the efficiency of Anisaldehyde. Those findings indicate that the An-(Ch-GA-GE) membrane has considerable potential for wound healing and skin regeneration.

Effective Elimination of Contaminant Antibiotics Using High-Surface-Area Magnetic-Functionalized Graphene Nanocomposites Developed from Plastic Waste.

The presence of pharmaceutical residues in aquatic environments represents a risk for the equilibrium of the ecosystem and may seriously affect human safety itself in the long term. To address this issue, we have synthesized functional materials based on highly-reduced graphene oxide (HRGO), sulfonated graphene (SG), and magnetic sulfonated graphene (MSG). The method of synthesis adopted is simple and inexpensive and makes use of plastic bottle waste as the raw material. We have tested the fabricated materials for their adsorption efficiency against two model antibiotics in aqueous solutions, namely Garamycin and Ampicillin. Our tests involved the optimization of different experimental parameters of the adsorption process, such as starting antibiotic concentration, amount of adsorbent, and time. Finally, we characterized the effect of the antibiotic adsorption process on common living organisms, namely Escherichia coli DH5α (E. coli DH5α) bacteria. The results obtained demonstrate the efficiency of the method in addressing the issue of the emergence of antibiotic-resistant bacteria, which will help in preventing changes in the ecosystem.

Fabrication of a novel low-cost superoleophilic nonanyl chitosan-poly (butyl acrylate) grafted copolymer for the adsorptive removal of crude oil spills.

A novel superoleophilic-hydrophobic nonanyl chitosan-poly (butyl acrylate) grafted copolymer was fabricated as a low-cost oil-adsorbent. Chitosan (CS) was coupled with a hydrophobic nonanal (N) to form nonanyl chitosan (NCS) schiff base, and followed by grafting with butyl acrylate monomers (ButA). The grafted copolymer was characterized by FTIR, TGA and SEM tools. The grafting percent was augmented and reached 88.5% with increasing ButA concentration up to 156 mM. Moreover, measurements of contact angle proved the superoleophilic character of NCS-g-poly (ButA) copolymer with an oil-contact angle 31°. Factors affecting the removal process such as contact time, oil type, oil dose, adsorbent dose, temperature and agitation speed were optimized. An increment in the oil removal (%) was observed with increasing the oil viscosity in the order of gasoil < mobil-1 oil < light crude oil < heavy crude oil. Besides, the adsorption process followed the pseudo-second order model and the equilibrium data were sufficiently fitted with the Langmuir model with a maximum adsorption capacity 108.79 g/g at 25 °C. Thermodynamic parameters computed from Van't Hoff plot confirmed the process to be exothermic, favorable and spontaneous. The results nominate the superoleophilic adsorbent as a potential oil- adsorbent for petroleum oil spills removal.

Fabrication of biodegradable gelatin/chitosan/cinnamaldehyde crosslinked membranes for antibacterial wound dressing applications.

This study intends to fabricate new biodegradable and antimicrobial membranes based on crosslinked gelatin/chitosan biopolymers. Cinnamaldehyde was incorporated into membranes for boosting their antimicrobial activities. FTIR spectroscopy and electronic spectrum analysis were used to prove their chemical structures, while SEM and TGA analysis were applied to investigate the morphological changes and the thermal properties of the crosslinked membranes. Moreover, ion exchange capacity, wettability and mechanical analysis were also conducted to get more information about the physicochemical properties for the developed membranes. Four different types of bacteria have been used for studying the antibacterial activities of the crosslinked membranes (one gram-positive and three gram-negative bacteria). The results showed a significant augmentation in the inhibition percent with increasing cinnamaldehyde content in the membrane matrix. Besides, hemocompatibility, biodegradability, and cytotoxicity studies were performed and the findings emphasized that the as-fabricated biodegradable gelatin/chitosan/cinnamaldehyde membranes could be efficiently used as antibacterial dressers for ameliorating the wound healing.

Development of amphoteric alginate/aminated chitosan coated microbeads for oral protein delivery.

A new amphoteric biopolymer carrier based on alginate and aminated chitosan coated microbeads (Alg/AmCS) was developed and characterized for bovine serum albumin (BSA) protein delivery. The amphoteric character was investigated through studying the swelling and in vitro BSA release behaviors of the developed microbeads in simulated gastric (SGF; pH1.2), intestinal (SIF; pH6.8), and colonic (SCF; pH7.4) fluids. The pH sensitivity was found to depend on the amount of AmCS in the coating medium. The results were interpreted from the view of the individual pH sensitivity of alginate and aminated chitosan in addition to the ionic interaction between them under the studied pHs. Besides; it was found that the BSA loading efficiency (LE) exceeded 82% regardless of the initial concentration of BSA. The released amount of BSA reached approximately 63% and 86% in SIF and SCF, respectively, using 0.25% AmCS. The stability of alginate microbeads in SCF was improved with increasing AmCS concentration in the coating medium up to 2%. Furthermore, the developed microbeads demonstrated their ability for biodegradation in addition to their antibacterial activities against selected bacterial strains. The results clearly suggested that Alg/AmCS coated microbeads could be suitable carriers for site-specific protein delivery in the intestinal and colon tracts.

Affinity covalent immobilization of glucoamylase onto ρ-benzoquinone activated alginate beads: I. Beads preparation and characterization.

ρ-Benzoquinone-activated alginate beads were presented as a new carrier for affinity covalent immobilization of glucoamylase enzyme. Evidences of alginate modification were extracted from FT-IR and thermal gravimetric analysis and supported by morphological changes recognized through SEM examination. Factors affecting the modification process such as ρ-benzoquinone (PBQ) concentration, reaction time, reaction temperature, reaction pH and finally alginate concentration, have been studied. Its influence on the amount of coupled PBQ was consequently correlated to the changes of the catalytic activity and the retained activity of immobilized enzyme, the main parameters judging the success of the immobilization process. The immobilized glucoamylase was found kept almost 80% of its native activity giving proof of non-significant substrate, starch, diffusion limitation. The proposed affinity covalent immobilizing technique would rank among the potential strategies for efficient immobilization of glucoamylase enzyme.

Affinity covalent immobilization of glucoamylase onto ρ-benzoquinone-activated alginate beads: II. Enzyme immobilization and characterization.

A novel affinity covalent immobilization technique of glucoamylase enzyme onto ρ-benzoquinone-activated alginate beads was presented and compared with traditional entrapment one. Factors affecting the immobilization process such as enzyme concentration, alginate concentration, calcium chloride concentration, cross-linking time, and temperature were studied. No shift in the optimum temperature and pH of immobilized enzymes was observed. In addition, K (m) values of free and entrapped glucoamylase were found to be almost identical, while the covalently immobilized enzyme shows the lowest affinity for substrate. In accordance, V (m) value of covalently immobilized enzyme was found lowest among free and immobilized counter parts. On the other hand, the retained activity of covalently immobilized glucoamylase has been improved and was found higher than that of entrapped one. Finally, the industrial applicability of covalently immobilized glucoamylase has been investigated through monitoring both shelf and operational stability characters. The covalently immobilized enzyme kept its activity over 36 days of shelf storage and after 30 repeated use runs. Drying the catalytic beads greatly reduced its activity in the beginning but recovered its lost part during use. In general, the newly developed affinity covalent immobilization technique of glucoamylase onto ρ-benzoquinone-activated alginate carrier is simple yet effective and could be used for the immobilization of some other enzymes especially amylases.

Toxoplasma antibodies in normal and complicated pregnancy.

A total of 70 women with complicated pregnancy and 20 ones with normal pregnancy were selected. They were all RH positive and free from syphilis, brucellosis and malignany. Both groups were subjected to detection of anti-Toxoplasma antibodies levels by the indirect haemagglutination tests (IHAT-IgG) and by ELISA (IgG and IgM). The results showed that all controls (normal pregnancy) were IHA-IgG and ELISA-IgM negative. However, two of the controls (10%) were ELISA. IgG positive. As to the women with complicated pregnancy 68/70 or 97.1% were IHAT positive. When using ELISA, 57/70 or 81.4% were IgG positive and 42/70 or 60% were IgM positive. The results revealed a significant difference between the complicated cases and controls. The diagnosis of abortion, stillbirth, premature labour, or neonatal death due to Toxoplasma infection needs careful and laborious evaluation. The use of ELISA (IgG & IgM) is a must, as it is more sensitive and specific than IHAT.

The impact of partial termination of food subsidy programme on food consumption pattern.

The aim of this study was to evaluate the public opinion towards the possible replacement of ration cards by cash payment and to investigate the effect of partial termination of food price subsidy programme on food consumption by families from different income brackets. A purposive sample of 300 families from Alexandria Governorates were interviewed to assess the attitude of the consumer towards the possible termination of current food subsidy programme. After one year, during which the subsidy programme was reduced, a follow up sample of 240 were interviewed. The results show that a large proportion of the families prefer the continuation of the current programme (80-81.2%), meanwhile, around 90% of them believed that subsidized foods do not reach the target group. The data show that subsidized meat and poultry are consumed by high income families while frozen subsidized fish was mostly consumed by poor families. The partial termination of the subsidy programme forced the families to reduce their consumption from sugar, tea, oil, and rice. During the second phase of the study. However the results show that high income families were least affected by the partial termination of the subsidy programme.

Impact of price hike on bread consumption in Egypt.

The aim of this study is to investigate the impact of price hike on bread consumption pattern. A purposive sample of 300 families was selected to represent low, middle and high income families. Bread consumption pattern was investigated including purchase of balady and french bread, daily percapita share from each type, number of left over loaves, methods of handling excess bread and consumers suggestions to improve bread quality. The data was collected over two phases, in the first phase the price of a loaf of bread was 2 P.T. The follow up data was collected after the price of a loaf of bread was increased to 5 P.T. The result show that balady bread was more frequently purchased by low income families, while french bread was consumed at a relatively higher rate by high income families particularly during the second phase of the study. The increase in the price of bread did not have any effect on the quantity purchased or on the number of left over loaves. However, the results show that there was a limited reduction in the quantity of bread wasted. The majority of the sample families accepted the present price of bread. However when given the choice, they preferred to reduce the weight of a loaf rather than increasing the price.