Fabrication and Characterization of Multifunctional Cellulose-based Nanostructures for Potential Biological Applications

Nowadays, there are many drugs were produced but sustainable drug delivery hardly to be achieved due to both poor selectivity and biodistribution. Besides that, some drugs such as antibiotics might not be effective against resistant strain bacteria and reduced effectiveness of antibiotics. Apart from that, increasing use of pesticide for treatment of rice blast which led to environmental issue such as water pollution. This has raised the demand for biodegradable nanomaterials offers an alternative approach for rice blast control instead of using pesticide. Therefore, cellulose was employed to drug delivery, antibacterial and antifungal applications due to its biodegradability and environmental friendliness. In this study, cellulose fibers isolated from paper wastes were functionalized via TEMPO-mediated oxidation to form carboxylic cellulose. Then, carboxylic cellulose acetate (CCA) was synthesized by reacting carboxylic cellulose with acetic anhydride in the presence of iodine as a catalyst. Next, CCA was prepared in the form of nanoparticles via nanoprecipitation. The obtained carboxylic cellulose acetate nanoparticles (CCA NPs) with a mean diameter of 96 nm were subsequently evaluated as the nanocarriers for the controlled release of drugs. Penicillin G as a model drug was loaded onto the CCA NPs via the adsorption process. Drug release profiles of Penicillin G from CCA NPs were evaluated in phosphate buffer solution (PBS) at different medium pH values (1.2, 7.4, and 8.6). Results showed that pH-responsive release of penicillin G from CCA NPs was released most slowly at a medium of pH 7.4 over 24 hours. In addition, preparation CCA NPs as an antibacterial nanocarrier and loaded with penicillin G against Gram (+) and Gram (-) bacteria was also explored. It was observed that prepared CCA NPs exhibited good antibacterial activity against methicillin resistant Staphylococcus aureus (MRSA) (+) Staphylococcus epidermis (+), Escherichia coli (-), Bacillus cereus (+), and Salmonella typhimurium (-). Also, loading of penicillin G onto CCA NPs could produce better antibacterial activities against both Gram (+) and Gram (-) bacteria strains. Interestingly, PenG-loaded CCA NPs against Methicillin resistant Staphylococcus aureus (MRSA) superbug which resistant to penicillin G has produced promising results with almost 98% of the bacterial cells were suppressed. This antibacterial study showed that antibiotics loaded CCA NPs has produced a synergistic effect as well as enhanced antibacterial activity against the growth of both Gram (+) and Gram (-) bacteria, strains tested. Apart from that, carboxylic cellulose was also further functionalized with a polyamine (PEI or PAMAM) via coupling reaction and used for nanoparticles synthesis. In addition, carboxylic cellulose was also fabricated into carboxylic cellulose nanoparticles via the nanoprecipitation process. The obtained carboxylic cellulose nanoparticles were undergoing further modification by incorporating metal ions via in situ approach to form metal functionalized carboxylated cellulose nanoparticles. The obtained cellulose derivatives nanoparticles were evaluated for antifungal activity against five isolates of pathogenic fungi (pyricularia oryzae). In vitro antifungal assay, indicated that that, PEI-cel NPs inhibit 28-49 % of Pyricularia oryzae at a concentration of 2 mg.mL-1. for metal functionalized carboxylic cellulose nanoparticles, Ag-carboxylated cellulose nanoparticles could inhibit almost 26-83.3 % of Pyricularia oryzae at a concentration of 0.25-2 mg.mL-1. Moreover, in the seed germination test, PEI-cel NPs and Ag-carboxylated cellulose nanoparticles exhibited a low phytotoxicity effect with germination rates of 66-97% and 81-98 %, respectively within a concentration of 0.125-4 mg.mL-1. These results revealed that the metal functionalized carboxylated cellulose nanoparticles and polyamine functionalized carboxylic cellulose nanoparticles can be potential candidates as the antifungal agent against rice blast fungi. Keywords: Carboxylic cellulose acetate nanoparticles, metal functionalized carboxylated cellulose nanoparticles, polyamine modified carboxylic cellulose nanoparticles, antifungal activity, antibacterial activity

Synthesis and antibacterial activity of azo and aspirin-azo derivatives [Sintesis dan aktiviti antibakteria terhadap azo dan terbitan azo-aspirin]

A series of azo derivatives (1a-e) were synthesized via coupling reaction with of overall yield 58 - 72% while aspirin-azo derivatives (2a-e) were prepared by esterification reaction of aspirin and azo derivatives (1a-e) with overall yield 38 - 75%. In this study, the structures of synthesized compounds were characterized using elemental analysis (CHN), nuclear magnetic resonance (1H NMR and 13C NMR) and Fourier Transform Infrared (FTIR) spectroscopy. The synthesized compounds were tested on antibacterial activity against Escherichia coli ATCC 25922 and Staphylococcus aureus S48/81 via turbidimetric kinetic method. The azo derivative-substituted fluorine, 1d showed the highest antibacterial activities against Escherichia coli ATCC 25922 and Staphylococcus aureus S48/81 compared with other synthesized compounds. However, synthesized aspirin-azo derivatives (2a-e) showed weak antibacterial activity against tested bacteria due to bulky molecular structure thus hindered the penetration into bacterial cell wall. © 2017, Malaysian Society of Analytical Sciences

Synthesis and Anticancer Activities of 4-[(Halophenyl)diazenyl]phenol and 4-[(Halophenyl)diazenyl]phenyl Aspirinate Derivatives against Nasopharyngeal Cancer Cell Lines

Aspirin and azo derivatives have been widely studied and have drawn considerable attention due to diverse biological activities. In this study, a series of 4-[(halophenyl)diazenyl]phenyl aspirinate derivatives were synthesized from the reaction of aspirin with 4-[(halophenyl)diazenyl]phenol via esterification, in the presence of DCC/DMAP in DCM with overall yield of 45–54%. 4- [(Halophenyl)diazenyl]phenol was prepared prior to esterification fromcoupling reaction of aniline derivatives and phenol in basic solution. All compounds were characterized using elemental analysis, FTIR, and 1H and 13C NMR spectroscopies. All compounds were screened for their anticancer activities against nasopharyngeal cancer (NPC) HK-1 cell lines and the viability of cultured cells was determined by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxylmethoxylphenyl)-2-(4-sulfophenyl)-2H-tetrazolium]- based colorimetric assay. 4-[(E)-(Fluorophenyl)diazenyl]phenol showed the highest anticancer activity against NPC HK-1 cell lines compared to other synthesized compounds. 4-[(Halophenyl)diazenyl]phenyl aspirinate showed low cytotoxicity against NPC HK-1 cell lines compared to 4-[(halophenyl)diazenyl]phenol but better anticancer activity than aspirin alone

Formulation of choline chloride/ascorbic acid natural deep eutectic solvent: Characterization, solubilization capacity and antioxidant property

In the present study, natural deep eutectic solvent composed of choline chloride and ascorbic acid (CHCL/AA NADES) was formulated for enhancing the solubility and antioxidant properties of antioxidant extracts from fruit wastes of Mangifera pajang. The solubilities of Mangifera pajang's antioxidant extracts in water and CHCL/AA NADES at different water contents (0–50 wt%) were investigated. It was observed that the antioxidant extracts were most soluble in the CHCL/AA NADES with 10 wt% of water, and the concentration of antioxidant was found to be approximately 15% and 4% as compared to water and pure CHCL/AA NADES, respectively. The positive effect of water on NADES can be related to the reduced viscosity of NADES, where the viscosity decreased up to 74% upon addition of water. Aside from that, all the tested CHCL/AA NADES enhanced the antioxidant capacity of antioxidant extracts by 1.3–14.64% compared to the antioxidant extracts in water. This finding highlights the role of CHCL/AA NADES as an antioxidant capacity enhancer. Noteworthy, the antioxidant extracts solubilized in the CHCL/AA NADES system formed a nano-scale cluster structure, as depicted by the TEM image, suggesting that the CHCL/AA NADES could potentially use in nanoformulation that provides protection to the antioxidant extracts

Chemical Characterization of Carbon Nanoparticles by Titration Method

Carbon nanoparticles (CNP) having below 10 nm in size. Firstly, in this study, starch nanoparticles were regenerated from sago starch by adding of starch solution into excess ethanol under controlled condition. After starch nanoparticles were obtained from available native sago starch. Then, it will be converted into carbon nanoparticles through process dehydration with concentrated acid such as sulphuric acid. Finally, carbon nanoparticles can be functionalized by nitric acid oxidation of carbon nanoparticles. The results of fourier transform infrared (FTIR) showed that carbonyl group peaks assigned at 1718 cm-1 and the UV-vis spectrometer showed that the wavelength of carbonyl group at 300 nm. When the concentration of nitric acid and reflux duration increases respectively, the titration method showed that amount of carboxylic groups were also increased. The optimum yield of COOH has been achieved is 1.5 % when carbon nanoparticles refluxed with 2M of nitric acid for 60 minutes

Synthesis and Biological Activities of Aspirin-Azo Derivatives

The chemistry of aspirin and azo derivatives has been widely studied for pharmaceutical purposes. In this study, a series of halogenated azo derivatives 47-49(a-d) and aspirinhalogenated azo derivatives 50-52(a-d) were successfully synthesised. Halogenated azo derivatives 47-49(a-d) were synthesized via coupling reaction while aspirin-halogenated azo derivatives 50-52(a-d) were synthesised via esterification reaction of aspirin with 47- 49(a-d). The structures of all the synthesized compounds were characterized by using elemental analysis (CHNS), nuclear magnetic resonance (1H NMR and 13C NMR) and Fourier Transform infrared (FTIR) spectroscopies. All compounds were evaluated for antibacterial activities against Escherichia coli ATCC 25922 and Staphylococcus aureus S48/81 via turbidimetric kinetic method. Compounds 47-49(a-d) showed good antibacterial activity against E. coli and S. aureus due to the presence of halogen substituents and -N=N- groups, which played significant role in antibacterial activities. The synthesised aspirin–halogenated azo derivatives 50-52(a-d) showed weak antibacterial activity against tested bacteria due to bulky molecular structure thus hindered the penetration into bacterial cell wall. All compounds were also further screened for their anticancer activities against nasopharyngeal cancer cell lines HK-1 using MTS [3-(4,5- dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide]-based colorimetric assay. Among 47-49(a-d), compound 47a and 49a showed good cell inhibition against HK-1. Aspirin–halogenated azo derivatives 50-52(a-d), on the other hand, exhibited weak cancer cells inhibition due to possible weak binding into EGFR tyrosine kinase

Antibacterial Studies of Penicillin G Loaded Carboxylic Cellulose Acetate Nanoparticles

Cellulose acetate nanoparticles (CCA NPs) with mean particles sizes of 97 nm were synthesized via the nanoprecipitation process. The antibacterial properties of these CCA NPs were evaluated against Gram (+) and Gram (-) bacteria, respectively. The CCA NPs exhibited good antibacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA) (+), Staphylococcus epidermis (+), Escherichia coli (-), Bacillus cereus (+), and Salmonella typhimurium (-) in range of MIC of 2.5×102 to 5.0×102 µg.mL-1 and MBC of 5.0×102 to 1.0×103 µg.mL-1. Penicillin G (PenG)- loaded CCA NPs demonstrated synergistic antibacterial activities against Gram (+) and Gram (-) bacteria. PenG-loaded CCA NPs also exhibited promising antimicrobial activity against the Methicillinresistant staphylococcus aureus (MRSA) superbug, which is resistant to penicillin G. These promising antibacterial properties suggested that CCA NPs could potentially serve as an alternative potent antimicrobial agent for both Gram (+) and Gram (-) bacteria as well as the superbug MRSA

pH-responsive carboxylic cellulose acetate nanoparticles for controlled release of penicillin G

In this study, pH responsive carboxylic cellulose acetate nanoparticles (CCA NPs) have been evaluated as drug nanocarriers for controlled release of drug. Herein, carboxylic cellulose acetate (CCA) was initially synthesized via oxidation of cellulose using a 2,2,6,6- tetramethylpiperidin-1-yl)oxidanyl (TEMPO) as an oxidant and followed by the acetylation of carboxylic cellulose in the presence of iodine as a catalyst. CCA NPs were then obtained via the nanoprecipitation process and subsequent sonication. The obtained CCA NPs with a mean diameter of 96 nm were subsequently evaluated as drug delivery nanocarriers. Penicillin G as a model drug was loaded onto the CCA NPs via the adsorption process. Drug release profiles of Penicillin G from CCA NPs were evaluated in phosphate buffer solution (PBS) at different medium pH values (1.2, 7.4, and 8.6). Release kinetic models were applied to determine the release mechanism of penicillin G from loaded CCA NPs. Results showed that pH-responsive release of penicillin G from CCA NPs which was released most slowly at medium of pH 7.4

Guidelines for the use and interpretation of assays for monitoring autophagy

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field