Tamer Mahmoud Tamer Abdelrazik

My research interests are largely directed toward utilized of natural or semi-natural polymer in different fields including biomedical, pharmaceutical and environmental applications. This droves me to get a lot of experience in the functionalization and formulation of polymers in different forms like sponges, membranes, hydrogels, and nano-particles. Currently, I am working in the generation of new antimicrobial polymers based on natural source (i.e., polysaccharide and proteins) via functionalized it with biocidal groups. In the same direction but different application, I am working in protection the RO membrane from biofouling by immobilized the surface

EDUCATION

I got my Ph.D. from Ain Shams University in Egypt. My thesis focused on the modification of chitosan for wound dressing application. That included the chemical functionalization of chitosan with various promising groups. Several techniques of preparation, characterization, and evaluation were studied and employed during that period

RESEARCH, TEACHING, or OTHER INTERESTS

Organic Chemistry, Polymers and Plastics, Materials Chemistry, Biomaterials

Scopus Publications

Taro leaf inspired micro/nanocellulose-based hierarchical structural coating and its application on O/W separation and food preservation
Md Mostafizur Rahman, Longhang Zhu, Ruotong Yao, Chao Wang, Tamer Mahmoud Tamer, Md Ahsan Habib, and Min Wu
Elsevier BV



Dichromate Contaminated Water Treatment using Novel Crystal Violet Azo Dye- Sulphonated Poly(Glycidyl methacrylate) Nano-Composite Adsorbent
Tamer M. Tamer, Randa E. Khalifa, Mortaga M. Abou-Krisha, Ahmed M. Omer, Abdulrahman G. Alhamzani, Mohamed E. Youssef, Tarek A. Yousef, Mostafa E. Salem, and Mohamed S. Mohy-Eldin
Springer Science and Business Media LLC
AbstractIn this study, the Cr(VI) metal ions have been removed from dichromate-contaminated water using a novel Azo Dye-Sulphonated Poly (glycidyl methacrylate) nano-composite adsorbent for the first time. Crystal violet Azo dye model (CV) has been immobilized onto nano-sulfonated Poly (glycidyl methacrylate) particles (SPGMA) through the adsorption process to obtain the novel crystal violet Azo Dye-Sulphonated Poly (glycidyl methacrylate) nano-composite adsorbent (CV-SPGMA). The effect of the adsorption conditions on the removal process of Cr (VI) metal ions such as dichromate concentration, adsorption time, temperature, pH, adsorbent dose, and finally agitation speed on the Cr(VI) metal ions removal was studied. The Cr(VI) metal ions removal process has been characterized using isotherms, kinetics, and thermodynamics models. The developed novel CV-SPGMA nano-composite adsorbent chemical structure and morphology were characterized using characterization tools such as FTIR, TGA, and SEM-EDAX analyses before and after the adsorption process. The developmentof the novel CV-SPGMA nano-composite adsorbent for the removal of Cr(VI) ions from dichromate-contaminated waters under mild adsorption conditions opens a new field of multiuse of the same adsorbent in the removal of more than one contaminant.


Crystal violet removal from waste water by sulfonated poly (glycidyl methacrylate) nano-adsorbent: optimization by response surface methodology, isotherms, kinetics, and thermodynamics studies
Randa E. Khalifa, Mortaga M. Abou-Krisha, Ahmed M. Omer, Abdulrahman G. Alhamzani, Mohamed E. Youssef, Tarek A. Yousef, Tamer M. Tamer, Mostafa E. Salem, and Mohamed S. Mohy-Eldin
Springer Science and Business Media LLC



Advances in stimuli-responsive polymeric hydrogels for anticancer drug delivery: A review
Ahmed M. Omer, Eman M. Abd El-Monaem, Abdelazeem S. Eltaweil, Tamer M. Tamer, Mohamed S. Mohy Eldin, Xiao-kun Ouyang, and Abolfazl Heydari
Elsevier BV



Novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogel development for Methyl orange removal from waste water
Ahmed M. Omer, Wagih A. Sadik, Rafik Abbas, Tamer M. Tamer, Mai M. Abd-Ellatif, and Mohamed S. Mohy-Eldin
Springer Science and Business Media LLC
AbstractIn the modern era, with the rapid growth of various industries, the issues of energy crisis and environmental pollution have garnered increasing attention. One significant source of industrial pollution is printing and dyeing wastewater. This wastewater often contains dyes that have aromatic structures and azo groups, such as Methyl orange (MO), which are both toxic and difficult to degrade. If these dyes are released into the wastewater stream without any treatment, they can have adverse effects on ecological balance and human health. Therefore, it is crucial to identify suitable treatment strategies to efficiently remove dyes from wastewater systems before discharge. In this study, the Methyl orange (MO) azo dye has been removed from dyes-contaminated wastewater, for the first time, using a novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogel (AECMC). Different characterization methods, including FTIR, TGA, and DSC were used to characterize the generated AECMC compounds. The water absorption and cationic exchange capacities were assessed. Factors affecting the MO anions adsorption including MO concentration, adsorption pH, temperature, time, adsorbent dose, and agitation speed have been investigated. Moreover, the kinetics of the adsorption process was assessed by the use of three models: pseudo-first-order, Pseudo-second-order, and Elovich. Moreover, the mechanism of the adsorption process was monitored using the Intraparticle diffusion and Boyd models. Additionally, the adsorption isotherm was examined using established models such as Langmuir, Freundlich, and Temkin isotherms. The thermodynamic characteristics of the MO adsorption process have been investigated at various adsorption temperatures using the Van't Hoff model. The results obtained from the study indicate that the process of MO adsorption adhered to the Pseudo-second-order kinetic model, the Langmuir isotherm model was found to be applicable, and spontaneous and exhibited an endothermic character. In conclusion, the developed novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogels (AECMC) have successive in the removal of the MO anionic dye from contaminated wastewater.


Development of novel amino-ethyl chitosan hydrogel for the removal of methyl orange azo dye model
Tamer M. Tamer, Rafik Abbas, Wagih A. Sadik, Ahmed M. Omer, Mai M. Abd-Ellatif, and Mohamed S. Mohy-Eldin
Springer Science and Business Media LLC
AbstractThe present study introduces a new and straightforward method for the amination of Chitosan. This method involves coupling Chitosan (CS) with 2-chloroethylamine (ENH2) in a single step to produce an amino-ethyl Chitosan derivatives with increased amine group content (CS-ENH2) using click chemistry. The resulting derivatives were then crosslinked using Glutaraldehyde to form amino-ethyl Chitosan Schiff bases. The novel amino-ethyl Chitosan Schiff bases were subsequently utilized as adsorbents for the removal of Methyl Orange (MO) dye from aqueous solutions using a batch technique, and the performance of the produced Schiff bases was compared with that of the native Chitosan Schiff base. The CS-ENH2 adsorbents show improved adsorption capacity up to 300% of the native Chitosan Schiff base with almost double removal rate. The adsorption temperature has a positive impact in general while almost 100% of MO removed at 60 °C using CS-ENH2 adsorbents compared with 66% of the native Chitosan Schiff base adsorbent. The adsorption pH shows a negative impact on the MO removal percent. That effect reduced sharply using the CS-ENH2 adsorbents with higher amination degree while the MO removal percent almost being constant over a wide range of pH; 2.0–7.0. The agitation speed has the same positive effect over all the adsorbents. However, the rate of MO removal percent decreased with increase the agitation speed up to 250 rpm. The experimental findings demonstrated that the highest percentage of MO dye removal was achieved under the conditions of pH 2.0, a temperature of 60 °C, agitation speed of 250 rpm, and adsorption duration of 90 min. These Schiff bases were subsequently characterized using advanced analytical techniques including Fourier Transform Infrared spectroscopy, Thermal analysis (TGA and DSC), and Scanning Electron Microscopy.


Nano-Sulphonated Poly (glycidyl methacrylate)-Hexamethyl Pararosaniline chloride novel composite adsorbent development for treatment of dichromate and permanganate contaminated waste water
T. Tamer, M. Abou-Krisha, A. Omer, A. Alhamzani, M. Youssef, T. Yousef, R. Khalifa, M. Salem, and M. Mohy-Eldin
Springer Science and Business Media LLC



Development of novel vanillylidene acetonyl chitosan Schiff base using click chemistry: antibacterial and antioxidant characters
T. M. Tamer, Guangyu Zhang, Mohamed S. Mohy-Eldin, and Zhaohui Su
Springer Science and Business Media LLC



Formulation of novel bioactive gelatin inspired by cinnamaldehyde for combating multi-drug resistant bacteria: Characterization, molecular docking, pharmacokinetic analyses, and in vitro assessments
Mohamed A. Hassan, Sarah Abd El-Aziz, Asmaa Nabil-Adam, and Tamer M. Tamer
Elsevier BV



Novel amino-ethyl Chitosan hydrogel for methyl orange removal from waste water: Kinetics, isotherms, and thermodynamics studies




Novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogel development for Methyl Orange Removal from Waste water: Kinetics, isotherms, and thermodynamics studies




Design of sulfonated polystyrene grafted cellulose acetate membrane for direct methanol fuel cells
Asmaa Attya Shalaby, Mohamed Hussien Abd Elmageed, Gihan Farouk Malash, Tamer Mahmoud Tamer, Ahmed Mohamed Omer, Mohamed Samir Mohy-Eldin, Zdenko Špitalský, and Randa Eslah Khalifa
Elsevier BV



Wheat husk-based sorbent as an economical solution for removal of oil spills from sea water
Basma M. Omar, Soad A. Abdelgalil, Hala Fakhry, Tamer M. Tamer, and Mervat A. El-Sonbati
Springer Science and Business Media LLC
AbstractOil spills are a significant threat to the marine ecosystem that requires immediate removal from the oceanic environment. Many technologies have been employed to clean up oil spills. Of these, adsorption has scored a prominent success due to the high efficiency, economic viability, environmental friendship, and ease of application. The utilization of agricultural waste to produce biosorbents have been considered as an ecofriendly and efficient approach for removing oil. Thus, a new low-cost oil adsorbent was prepared via esterification of the wheat straw (Str) with a hydrophobic benzoyl group, the resulting copolymer (Str-co-Benz) was characterized by FTIR, TGA, DSC, and SEM and used at laboratory scale. The oil spill cleanup process was conducted using a crude oil-natural seawater system under different adsorption conditions such as oil concentration, adsorbent dose, agitation time and speed. Equilibrium studies were performed to determine the capacity of the prepared materials for crude oil adsorption. Langmuir and Freundlich adsorption models were used to describe the experimental isotherms. The reliability of the data was examined and evaluated via application of response surface methodology program. The results showed that oil adsorption followed a pseudo-second-order kinetic model and fitted well with Langmuir model with a maximum adsorption capacity of 10.989 and 12.786 g/g for Str and (Str-co-Benz), respectively. Overall, the modified wheat husk is an effective platform for removing oil from marine ecosystems due to low cost, biodegradability, simple synthesis and fast removal. Moreover, the resulted solid can be used as a fuel in some industrial processes such as steam boilers and brick production incinerators.


Synthesis and physicochemical properties of an aromatic chitosan derivative: In vitro antibacterial, antioxidant, and anticancer evaluations, and in silico studies
Tamer M. Tamer, Hongyan Zhou, Mohamed A. Hassan, Marwa M. Abu-Serie, Sergey Shityakov, Smaher M. Elbayomi, Mohamed S. Mohy-Eldin, Yongcheng Zhang, and Tuckyun Cheang
Elsevier BV



Kinetics, isotherms and thermodynamics of oil spills removal by novel amphiphilic Chitosan-g-Octanal Schiff base polymer developed by click grafting technique
Bassant Yousry Eweida, Ahmed Mohamed Omer, Tamer Mahmoud Tamer, Hesham Abd-Elfatah Mohamed Soliman, Ahmed Amin Zaatot, and Mohamed Samir Mohy-Eldin
Springer Science and Business Media LLC
AbstractKinetic, isothermal and thermodynamic studies for the oil spills removal process have been conducted by Chitosan and novel amphiphilic Chitosan-g-Octanal Schiff base adsorbents developed by click chemistry and evaluated successfully in the removal of heavy crude oil spills. Chitosan was first prepared from wastes of marine shrimp shells, and then Chitosan and Chitosan-g-Octanal Schiff base adsorbents were synthesized and verified their structures, thermal stability and their morphological changes using FT-IR spectroscopy, TGA and SEM. The oil adsorption percentages (%) using heavy crude oil were 96.41% for the Chitosan-g-Octanal Schiff base adsorbent compared to 64.99% for native Chitosan counterpart. High rate of adsorption was observed where 40% of oil adsorbed within 15 min only using the Chitosan-g-Octanal Schiff base adsorbent compared to 90 min for native Chitosan adsorbent. 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 30.30 g/g at 25 °C. Thermodynamic parameters computed from Van’t Hoff plot confirmed the process to be endothermic, favorable and spontaneous.


Functionalization of chitosan with poly aromatic hydroxyl molecules for improving its antibacterial and antioxidant properties: Practical and theoretical studies
Tamer M. Tamer, Mervat M. ElTantawy, Arina Brussevich, Anna Nebalueva, Alexander Novikov, Ivan V. Moskalenko, Marwa M. Abu-Serie, Mohamed A. Hassan, Svetlana Ulasevich, and Ekaterina V. Skorb
Elsevier BV



Therapeutic potential of two formulated novel chitosan derivatives with prominent antimicrobial activities against virulent microorganisms and safe profiles toward fibroblast cells
Mohamed A. Hassan, Tamer M. Tamer, Ahmed M. Omer, Walid M.A. Baset, Eman Abbas, and Mohamed S. Mohy-Eldin
Elsevier BV



Interaction of Jania rubens Polyphenolic Extract as an Antidiabetic Agent with α-Amylase, Lipase, and Trypsin: In Vitro Evaluations and In Silico Studies
Asmaa Nabil-Adam, Mohamed L. Ashour, Tamer M. Tamer, Mohamed A. Shreadah, and Mohamed A. Hassan
MDPI AG
Jania rubens red seaweed has various bioactive compounds that can be used for several medicinal and pharmaceutical applications. In this study, we investigate the antidiabetic, anti-inflammatory, and antioxidant competency of Jania rubens polyphenolic extract (JRPE) by assessing their interactions with α-amylase, lipase, and trypsin enzymes. HPLC analysis revealed the dominance of twelve polyphenolic compounds. We performed computational analysis using α-amylase, lipase, and trypsin as target proteins for the polyphenols to explore their activities based on their predicted modes of binding sites following molecular modeling analysis. The molecular docking analysis demonstrated a good affinity score with a noticeable affinity to polyphenolic compositions of Jania rubens. The compounds with the highest affinity score for α-amylase (PDB: 4W93) were kaempferol, quercetin, and chlorogenic acid, with −8.4, −8.8 and −8 kcal/mol, respectively. Similarly, lipase (PDB: 1LPB) demonstrated high docking scores of −7.1, −7.4, and −7.2 kcal/mol for kaempferol, quercetin, and chlorogenic acid, respectively. Furthermore, for trypsin (PDB: 4DOQ) results, kaempferol, quercetin, and chlorogenic acid docking scores were −7.2, −7.2, and −7.1 kcal/mol, respectively. The docking findings were verified using in vitro evaluations, manifesting comparable results. Overall, these findings enlighten that the JRPE has antidiabetic, anti-inflammatory, and antioxidant properties using different diabetics’ enzymes that could be further studied using in vivo investigations for diabetes treatment.


Fabrication of Grafted Carboxymethyl Cellulose Superabsorbent Hydrogel for Water Retention and Sustained Release of Ethephon in Sandy Soil
Ahmed M. Omer, Tamer M. Tamer, Mohamed E. Hassan, Randa E. Khalifa, Eman M. Abd El-Monaem, Abdelazeem S. Eltaweil, and Mohamed S. Mohy Eldin
Springer Science and Business Media LLC
AbstractThe present study aimed to develop an efficient superabsorbent hydrogel for water conservation and slow release of Ethephon in sandy soil. Herein, carboxymethyl cellulose (CMC) was grafted via a free radical polymerization technique with acrylamide and 2-Acrylamido-2-methylpropanesulfonic acid (AMPS) as hydrophilic monomers. The developed CMC-g-(PAM-co-PAMPS) graft copolymer superabsorbent hydrogel was characterized by FTIR, TGA, and SEM analysis to prove the occurrence of the grafting process. Several factors affecting the grafting process were investigated, while maximum grafting (%) value reached 91%. Moreover, increasing AMPS ratio obviously improved the swelling degree of the developed hydrogel with a maximal value of 17,770%. Moreover, addition of 2% of hydrogel to sandy soil potentially enhanced the water retention by 47% compared to pure sandy soil which retained about 7% of water. Besides, increasing Ethephon ratio up to 20% significantly increased its loading (%) value up to 88%, while about 87% of Ethephon was released within 28 days in a slow and sustained manner. The results suggested that the fabricated grafted hydrogel can serve as nutrient carrier and amendment for sandy soil for advanced agricultural applications.


Carboxymethyl cellulose/sericin-based hydrogels with intrinsic antibacterial, antioxidant, and anti-inflammatory properties promote re-epithelization of diabetic wounds in rats
Lamia M. El-Samad, Mohamed A. Hassan, Amal A. Basha, Saeed El-Ashram, Eman H. Radwan, Karoline K. Abdul Aziz, Tamer M. Tamer, Maria Augustyniak, and Abeer El Wakil
Elsevier BV



Influence of Cedar Essential Oil on Physical and Biological Properties of Hemostatic, Antibacterial, and Antioxidant Polyvinyl Alcohol/Cedar Oil/Kaolin Composite Hydrogels
Tamer M. Tamer, Maysa M. Sabet, Zahrah A. H. Alhalili, Ahmed M. Ismail, Mohamed S. Mohy-Eldin, and Mohamed A. Hassan
MDPI AG
Polyvinyl alcohol (PVA) is a safe and biodegradable polymer. Given the unique physical and chemical properties of PVA, we physically cross-linked PVA with kaolin (K) and cedar essential oil (Ced) using the freeze-thawing approach to fabricate PVA/Ced/K sponge hydrogels as hemostatic, antibacterial, and antioxidant wound healing materials. The physicochemical characteristics of PVA/Ced/K hydrogels, including water swelling profiles and gel fractions, were surveyed. Additionally, the functional groups of hydrogels were explored by Fourier transform infrared spectroscopy (FTIR), while their microstructures were studied using scanning electron microscopy (SEM). Furthermore, the thermal features of the hydrogels were probed by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Evidently, alterations in cedar concentrations resulted in significant variations in size, water uptake profiles, and hydrolytic degradation of the hydrogels. The incorporation of cedar into the PVA/K endowed the hydrogels with significantly improved antibacterial competency against Bacillus cereus (B. cereus) and Escherichia coli (E. coli). Moreover, PVA/Ced/K exhibited high scavenging capacities toward ABTS•+ and DPPH free radicals. Beyond that, PVA/Ced/K hydrogels demonstrated hemocompatibility and fast blood clotting performance in addition to biocompatibility toward fibroblasts. These findings accentuate the prospective implementation of PVA/Ced/K composite hydrogel as a wound dressing.


Development of Azo Dye Immobilized Sulfonated Poly (Glycidyl Methacrylate) Polymer Composite as Novel Adsorbents for Water Treatment Applications: Methylene Blue Immobilization Isotherm, Kinetic, Thermodynamic, and Simulations Studies
Mohamed R. El-Aassar, Tamer M. Tamer, Mohamed Y. El-Sayed, Ahmed M. Omer, Ibrahim O. Althobaiti, Mohamed E. Youssef, Rawan F. Alolaimi, Emam F. El-Agammy, Manar S. Alruwaili, Omar O. Rabhy,et al.
MDPI AG
Methylene blue (MB) immobilized onto a sulfonated poly(glycidyl methacrylate) (SPGMA) polymer composite has been developed as a novel adsorbent for water treatment applications. The MB adsorptions onto sulfonated poly(glycidyl methacrylate) polymer characters have been studied. The adsorption isotherms, namely Langmuir and Freundlich, have been investigated. Other isotherm models. As a compromise between the Freundlich and Langmuir isotherm models, such as the D–R isotherm and the Temkin isotherm, have been compared. The results indicated that the adsorption process followed the Freundlich isotherm model, indicating heterogeneous surface site energies and multi-layer levels of sorption. This study selected three linear kinetic models, namely pseudo-first order, pseudo-second order, and Elovich, to describe the MB sorption process using SPGMA negatively charged nanoparticles (430 nm). The obtained data revealed that the adsorption process obeyed the pseudo-second-order kinetic model, suggesting that the rate-limiting step in these sorption processes may be chemisorption. Furthermore, the thermodynamic parameters have been evaluated. Moreover, the interaction of the MB molecules with SPGMA nanoparticles has been simulated using the governing equation that describes ion exchange resin derived from Nernst—Plank equations between two ion species. Finally, the developed MB-SPGMA composite adsorbent (27 mg/g) wastested for the first time for the removal of Cr6+ ions and Mn7+ metal ions from dichromate and permanganate-contaminated waters under mild adsorption conditions, opening a new field of multiuse of the same adsorbent in the removal of more than one contaminant.


Development of Azo Dye Immobilized Poly (Glycidyl Methacrylate-Co-Methyl Methacrylate) Polymers Composites as Novel Adsorbents for Water Treatment Applications: Methylene Blue-Polymers Composites
Mohamed R. El-Aassar, Tamer M. Tamer, Mohamed Y. El-Sayed, Ahmed M. Omer, Ibrahim O. Althobaiti, Mohamed E. Youssef, Rawan F. Alolaimi, Emam F. El-Agammy, Manar S. Alruwaili, and Mohamed S. Mohy-Eldin
MDPI AG
Methylene blue azo dye (MB) immobilized onto Poly (glycidyl methacrylate-Co-methyl methacrylate), (PGMA-co-PMMA), and sulphonated Poly (glycidyl methacrylate-Co-methyl methacrylate), (SPGMA-co-PMMA), polymers composites have been developed as novel adsorbents for water treatment applications. The effect of copolymer composition and sulphonation on the MB content has been studied. Maximum MB content was correlated to the Polyglycidyl methacrylate content for both native and sulphonated copolymers. Furthermore, the effect of the adsorption conditions on the MB content was studied. Sulfonated Poly (glycidyl methacrylate; SPGMA) was the most efficient formed composite with the highest MB content. The developed composites’ chemical structure and morphology were characterized using characterization tools such as particle size, FTIR, TGA, and SEM analyses. The developed MB-SPGMA composite adsorbent (27 mg/g), for the first time, was tested for the removal of Cr (VI) ions and Mn (VII) metal ions from dichromate and permanganate contaminated waters under mild adsorption conditions, opening a new field of multiuse of the same adsorbent in the removal of more than one contaminants.


Preparation and Physicochemical Characterization of Gelatin–Aldehyde Derivatives
Mahmoud Atya El-Meligy, Katarína Valachová, Ivo Juránek, Tamer M. Tamer, and Ladislav Šoltés
MDPI AG
The present study aimed at preparing novel free-radical scavenging and water-soluble compounds derived from gelatin. Specifically, gelatin–syringaldehyde, gelatin–anisaldehyde, and gelatin–vanillin were synthesized and thoroughly studied for their physicochemical properties. In particular, the compounds were characterized by UV-Vis spectroscopy, Fourier-transform infrared spectroscopy, and scanning electron microscopy. Notably, as demonstrated by thermogravimetry and differential scanning calorimetry, all three derivatives exhibited higher thermal stability than gelatin itself. Free-radical scavenging activities of the examined compounds were explored by (i) a standard spectrophotometric ABTS assay and (ii) an assay of oxidative degradation of hyaluronic acid monitored by rotational viscometry. We found that gelatin and gelatin–syringaldehyde demonstrated the highest efficacy in scavenging •OH radicals, whereas gelatin–anisaldehyde was the least effective. The efficacy of scavenging alkyloxy- and alkylperoxy-type free radicals via hydrogen-atom-transferring property was in the following order: gelatin > gelatin–vanillin > gelatin–syringaldehyde > gelatin–anisaldehyde. Electron-donor properties determined using the ABTS assay revealed the following order in one-electron reduction of ABTS•+: gelatin > gelatin–anisaldehyde > gelatin–vanillin > gelatin–syringaldehyde.


Preparation, Characterization, and Bio Evaluation of Fatty N- Hexadecanyl Chitosan Derivatives for Biomedical Applications
Hanaa Mansour, Samia El-Sigeny, Sarah Shoman, Marwa M. Abu-Serie, and Tamer M. Tamer
MDPI AG
The objective of this study was to improve the antibacterial activities of chitosan via N-alkyl substitution using 1-bromohexadecane. Mono and di substitution (Mono-NHD-Ch and Di-NHD-Ch) were prepared and characterized using FT-IR, HNMR, TGA, DSC, and SEM. Elemental analysis shows an increase in the C/N ratio from 5.45 for chitosan to 8.63 for Mono-NHD-Ch and 10.46 for Di-NHD-Ch. The antibacterial properties were evaluated against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus. In the examined microorganisms, the antibacterial properties of the novel alkyl derivatives increased substantially higher than chitosan. The minimum inhibitory concentration (MIC) of Mono-NHD-Ch and Di-NHD-Ch was perceived at 50 μg/mL against tested microorganisms, except for B. cereus. The MTT test was used to determine the cytotoxicity of the produced materials, which proved their safety to fibroblast cells. The findings suggest that the new N-Alkyl chitosan derivatives might be used as antibacterial alternatives to pure chitosan in wound infection treatments.

RECENT SCHOLAR PUBLICATIONS

Taro leaf inspired micro/nanocellulose-based hierarchical structural coating and its application on O/W separation and food preservation
MM Rahman, L Zhu, R Yao, C Wang, TM Tamer, MA Habib, M Wu
Carbohydrate Polymers, 123493 2025



Application of Nanocellulose in Solar Photo/Thermal Energy Conversion and Electrochemical Energy Storage Devices
C Wang, L Zhu, X Wang, TM Tamer, R Yao, MM Rahman, L Zhang, M Wu
Green Carbon 2025



Dichromate Contaminated Water Treatment using Novel Crystal Violet Azo Dye-Sulphonated Poly (Glycidyl methacrylate) Nano-Composite Adsorbent
TM Tamer, RE Khalifa, MM Abou-Krisha, AM Omer, AG Alhamzani, ...
Water, Air, & Soil Pollution 236 (1), 1-21 2025



Crystal violet removal from waste water by sulfonated poly (glycidyl methacrylate) nano-adsorbent: optimization by response surface methodology, isotherms, kinetics, and
RE Khalifa, MM Abou-Krisha, AM Omer, AG Alhamzani, ME Youssef, ...
Polymer Bulletin 82 (1), 165-196 2025



Advances in stimuli-responsive polymeric hydrogels for anticancer drug delivery: A review
AM Omer, EM Abd El-Monaem, AS Eltaweil, TM Tamer, MSM Eldin, ...
Journal of Drug Delivery Science and Technology, 106394 2024



Nano-Sulphonated Poly (glycidyl methacrylate)-Hexamethyl Pararosaniline chloride novel composite adsorbent development for treatment of dichromate and permanganate contaminated
T Tamer, M Abou-Krisha, A Omer, A Alhamzani, M Youssef, T Yousef, ...
Adsorption 30 (6), 877-890 2024



Novel amino-ethyl carboxymethyl cellulose crosslinked ampholyte hydrogel development for Methyl orange removal from waste water
AM Omer, WA Sadik, R Abbas, TM Tamer, MM Abd-Ellatif, MS Mohy-Eldin
Scientific Reports 14 (1), 14701 2024



Development of novel vanillylidene acetonyl chitosan Schiff base using click chemistry: antibacterial and antioxidant characters
TM Tamer, G Zhang, MS Mohy-Eldin, Z Su
Polymer Bulletin 81 (9), 8489-8509 2024



Formulation of novel bioactive gelatin inspired by cinnamaldehyde for combating multi-drug resistant bacteria: characterization, molecular docking, pharmacokinetic analyses
MA Hassan, S Abd El-Aziz, A Nabil-Adam, TM Tamer
International Journal of Pharmaceutics 652, 123827 2024



Development of novel amino-ethyl chitosan hydrogel for the removal of methyl orange azo dye model
TM Tamer, R Abbas, WA Sadik, AM Omer, MM Abd-Ellatif, MS Mohy-Eldin
Scientific Reports 14 (1), 1284 2024



Fabrication, Properties, and Stability of Frankincense Oil and Fatty Chitosan/Polyvinyl Alcohol-Based Wound-Healing Hydrogels
HA Mansour, T Tamer
Delta Journal of Science 48 (1), 70-93 2024



Novel amino-ethyl Chitosan hydrogel for methyl orange removal from waste water: Kinetics, isotherms, and thermodynamics studies
TM Tamer, WAA Sadik, RA Elady, AM Omer, MM Abd-Ellatif, ...
Desalination and Water Treatment 317, 100122 2024



Design of sulfonated polystyrene grafted cellulose acetate membrane for direct methanol fuel cells
AA Shalaby, MH Abd Elmageed, GF Malash, TM Tamer, AM Omer, ...
Solid State Ionics 404, 116420 2024



Synthesis and physicochemical properties of an aromatic chitosan derivative: In vitro antibacterial, antioxidant, and anticancer evaluations, and in silico studies
TM Tamer, H Zhou, MA Hassan, MM Abu-Serie, S Shityakov, ...
International Journal of Biological Macromolecules 240, 124339 2023



Kinetics, isotherms and thermodynamics of oil spills removal by novel amphiphilic Chitosan-g-Octanal Schiff base polymer developed by click grafting technique
BY Eweida, AM Omer, TM Tamer, HAEM Soliman, AA Zaatot, ...
Polymer Bulletin 80 (5), 4813-4840 2023



Functionalization of chitosan with poly aromatic hydroxyl molecules for improving its antibacterial and antioxidant properties: practical and theoretical studies
TM Tamer, MM ElTantawy, A Brussevich, A Nebalueva, A Novikov, ...
International Journal of Biological Macromolecules 234, 123687 2023



Therapeutic potential of two formulated novel chitosan derivatives with prominent antimicrobial activities against virulent microorganisms and safe profiles toward fibroblast cells
MA Hassan, TM Tamer, AM Omer, WMA Baset, E Abbas, MS Mohy-Eldin
International Journal of Pharmaceutics 634, 122649 2023



Interaction of Jania rubens Polyphenolic Extract as an Antidiabetic Agent with α-Amylase, Lipase, and Trypsin: In Vitro Evaluations and In Silico Studies
A Nabil-Adam, ML Ashour, TM Tamer, MA Shreadah, MA Hassan
Catalysts 13 (2), 443 2023



Wheat husk-based sorbent as an economical solution for removal of oil spills from sea water
BM Omar, SA Abdelgalil, H Fakhry, TM Tamer, MA El-Sonbati
Scientific Reports 13 (1), 2575 2023



Fabrication of grafted carboxymethyl cellulose superabsorbent hydrogel for water retention and sustained release of ethephon in sandy soil
AM Omer, TM Tamer, ME Hassan, RE Khalifa, EM Abd El-Monaem, ...
Arabian Journal for Science and Engineering 48 (1), 561-572 2023

MOST CITED SCHOLAR PUBLICATIONS

Hyaluronan and synovial joint: function, distribution and healing
TM Tamer
Interdiscip Toxicol 6 (3), 111–125 2013
Citations: 393



Poly (vinyl alcohol)-alginate physically crosslinked hydrogel membranes for wound dressing applications: characterization and bio-evaluation
EA Kamoun, ERS Kenawy, TM Tamer, MA El-Meligy, MSM Eldin
Arabian Journal of Chemistry 8 (1), 38-47 2015
Citations: 357



Preparation, physicochemical characterization and antimicrobial activities of novel two phenolic chitosan Schiff base derivatives
MA Hassan, AM Omer, E Abbas, WMA Baset, TM Tamer
Scientific reports 8 (1), 11416 2018
Citations: 241



Fabrication of biodegradable gelatin/chitosan/cinnamaldehyde crosslinked membranes for antibacterial wound dressing applications
E Kenawy, AM Omer, TM Tamer, MA Elmeligy, MSM Eldin
International Journal of Biological Macromolecules 139, 440-448 2019
Citations: 159



Synthesis, characterization and antimicrobial evaluation of two aromatic chitosan Schiff base derivatives
TM Tamer, MA Hassan, AM Omer, WMA Baset, ME Hassan, ...
Process Biochemistry 51 (10), 1721-1730 2016
Citations: 158



Co-encapsulation of Vitamin C and β-Carotene in liposomes: Storage stability, antioxidant activity, and in vitro gastrointestinal digestion
X Liu, P Wang, YX Zou, ZG Luo, TM Tamer
Food Research International 136, 109587 2020
Citations: 154



Antibacterial and antioxidative activity of O-amine functionalized chitosan
TM Tamer, MA Hassan, AM Omer, K Valachov, MSM Eldin, MN Collins, ...
Carbohydrate polymers 169, 441-450 2017
Citations: 139



Chitosan/hyaluronan/edaravone membranes for anti-inflammatory wound dressing: In vitro and in vivo evaluation studies
TM Tamer, K Valachov, MA Hassan, AM Omer, M El-Shafeey, MSM Eldin, ...
Materials Science and Engineering: C 90, 227-235 2018
Citations: 134



Green synthesis of platinum nanoparticles using Atriplex halimus leaves for potential antimicrobial, antioxidant, and catalytic applications
AS Eltaweil, M Fawzy, M Hosny, EM Abd El-Monaem, TM Tamer, ...
Arabian Journal of Chemistry 15 (1), 103517 2022
Citations: 133



Antioxidant and antibacterial polyelectrolyte wound dressing based on chitosan/hyaluronan/phosphatidylcholine dihydroquercetin
MA Hassan, TM Tamer, K Valachov, AM Omer, M El-Shafeey, MSM Eldin, ...
International Journal of Biological Macromolecules 166, 18-31 2021
Citations: 127



Hemostatic and antibacterial PVA/Kaolin composite sponges loaded with penicillin–streptomycin for wound dressing applications
TM Tamer, MM Sabet, AM Omer, E Abbas, AI Eid, MS Mohy-Eldin, ...
Scientific Reports 11 (1), 3428 2021
Citations: 125



Comprehensive insights into microbial keratinases and their implication in various biotechnological and industrial sectors: A review
MA Hassan, D Abol-Fotouh, AM Omer, TM Tamer, E Abbas
International journal of biological macromolecules 154, 567-583 2020
Citations: 115



Evaluation of antimicrobial and antioxidant activities for cellulose acetate films incorporated with Rosemary and Aloe Vera essential oils
GF El Fawal, AM Omer, TM Tamer
Journal of food science and technology 56, 1510-1518 2019
Citations: 101



MitoQ loaded chitosan-hyaluronan composite membranes for wound healing
TM Tamer, MN Collins, K Valachov, MA Hassan, AM Omer, ...
Materials 11 (4), 569 2018
Citations: 95



Development of amphoteric alginate/aminated chitosan coated microbeads for oral protein delivery
AM Omer, TM Tamer, MA Hassan, P Rychter, MSM Eldin, N Koseva
International journal of biological macromolecules 92, 362-370 2016
Citations: 90



Antibacterial activity of chitosan chemically modified with new technique
MSM Eldin, EA Soliman, AI Hashem, TM Tamer
Trends Biomater Artif Organs 22 (3), 125-137 2008
Citations: 90



Insight into multidrug-resistant microorganisms from microbial infected diabetic foot ulcers
MA Hassan, TM Tamer, AA Rageh, AM Abou-Zeid, EHF Abd El-Zaher, ...
Diabetes & Metabolic Syndrome: Clinical Research & Reviews 13 (2), 1261-1270 2019
Citations: 89



Cinnamyl O-amine functionalized chitosan as a new excipient in direct compressed tablets with improved drug delivery
G Ren, C Clancy, TM Tamer, B Schaller, GM Walker, MN Collins
International Journal of Biological Macromolecules 141, 936-946 2019
Citations: 83



Antimicrobial activity of novel aminated chitosan derivatives for biomedical applications
MS Mohy Eldin, EA Soliman, AI Hashem, TM Tamer
Advances in Polymer Technology 31 (4), 414-428 2012
Citations: 82



Formation of zinc oxide nanoparticles using alginate as a template for purification of wastewater
TM Tamer, WM Abou-Taleb, GD Roston, MS Mohyeldin, AM Omer, ...
Environmental nanotechnology, monitoring & management 10, 112-121 2018
Citations: 77