Browsing by Author "Ishak Ahmad"
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Publication Cytotoxicity of VCO Microemulsion Developed Using Non-Ionic Surfactants Mixture against Normal L6 Cell and Optimisation its Formulation Containing Curcumin(Universiti Sains Islam Malaysia, 2019) ;Kharis Zahid ;Nadia Halib ;Ishak Ahmad ;Zainah AdamRazali MiradThe objective of the study was to evaluate the properties of curcumin formulated in Virgin Coconut Oil (VCO) microemulsion system developed using food-acceptable grade surfactants of Tween 80, Span 80 and Span 40. Cytotoxicity analysis was carried out toward VCO microemulsion using normal L6 cells in vitro. The microemulsion was formulated using VCO as the oil phase with non-ionic surfactants mixture consist of Tween 80, Span 80 and Span 40. Curcumin was incorporated into VCO microemulsion as a cold mixture under mild agitation to form curcumin microemulsion. The physical stability of curcumin microemulsion was investigated and its characterisations were further studied according to its appearance (visual), morphology, turbidity, pH, droplet size, viscosity, conductivity, and polydispersity index. Based on the results of optimisation studies, the final 0.1 % (w/w) of curcumin concentration was successfully loaded into VCO microemulsion system. This formulation had clear transparent yellow curcumin colour without phase separation. The results indicated that the curcumin microemulsion had an average particle size about 43.15 nm and good stability with zeta potential -0.24 mV. The curcumin micoemulsion morphology had spherical in shape when observed under transmission electron microscopy (TEM), the curcumin microemulsion was slightly acidic with pH value 5.28, the conductivity was 241.2 ?S/cm and the viscosity was 8.5 cP. - Some of the metrics are blocked by yourconsent settings
Publication Pengembungan Hidrogel Selulosa Bakteria-asid Akrilik : Sensitiviti Terhadap Rangsangan Luar(Penerbit UKM, 2009) ;Nadia Halib ;Mohd Cairul Iqbal Mohd Amin ;Ishak Ahmad ;Zulkifli Mohamed HashimNoriah JamalThis study evaluated various environmental factors affecting the swelling degree of bacterial cellulose-acrylic acid hydrogels. Aqueous bacterial cellulose-acrylic acid (4:1) mixtures were prepared and subjected to electron beam irradiation at 30 and 50 kGy. Swelling rate under influenced of pH, temperature and ionic strength was investigated from 1 to 24 hours. Swelling degree of hydrogels was dependent on irradiation dose: those synthesized at 50 kGy exhibited significant higher swelling degree (p<0.0001) in methanol (619%) compared to water (510%) at room temperature after 24 hours. External ionic strength affected swelling, i.e, elevation in sodium chloride concentration decreased swelling degree. Hydrogels were also sensitive to pH: swelling increased with increasing pH and was optimal at pH 7. Swelling also increased with increasing temperature from 25¡C to 50¡C. In conclusion, the ability of electron irradiated bacterial cellulose-acrylic acid hydrogels to respond to various external environment make it a material to be developed as an active delivery system for drugs, proteins and hormones. - Some of the metrics are blocked by yourconsent settings
Publication Pengintegrasian Sains Tauhidik: Persepsi Peserta(Universiti Sains Islam Malaysia, 2017) ;Ishak Ahmad ;Faszly Rahim ;Zanaton H. Iksan ;Wan Nasyruddin Wan Abdullah ;Normazida Rozi ;Mohammad Faris Mohammad Esa ;Ishak Ahmad ;Rizafizah Othaman ;Nurul Huda Abd. Karim ;Nurul Izzaty Hassan ;Rozida Mohd. KhalidAzizah Baharom@Abd. AzizKimia merupakan salah satu cabang ilmu sains yang telah lama dipelopori oleh ilmuwan Islam. Walau bagaimanapun, sekularisme telah menjadikan sains terpinggir dari Islam, apatah lagi merapatkan hubungan di antara manusia dan Pencipta. Seminar Sains Tauhidik telah diadakan untuk menghebahkan pengetahuan dan penemuan oleh penyelidik dari latar belakang sains dan pengajian Islam kepada pelajar dan pensyarah di Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia. Borang soal selidik tentang pemahaman dan persepsi berkenaan penyepaduan sains dan Islam telah diagihkan kepada peserta selepas tamat seminar. Hasil kajian mendapati 93.8% responden meminati sains tetapi hanya 63.1% pernah didedahkan kepada pembelajaran berintegrasi sains dan Islam. Selain itu, 63.1% memahami maksud sekularisme dan 69.2% menyedari unsur kimia ada disebut di dalam al-Quran. Kajian ini juga menunjukkan bahawa lebih 90% responden bersetuju sains dan Islam dikaitkan dengan cara bersepadu. Kesimpulannya, integrasi sains dan Islam atau Sains Tauhidik memandu kita meneroka dan mempelajari tentang alam ini melalui aktiviti sains berlandaskan Islam berpandukan al-Quran dan hadis. Oleh itu, usaha-usaha yang lebih proaktif dan holistik perlu dilakukan untuk mendidik dan mengukuhkan kefahaman Sains Tauhidik kepada pelajar seawal di sekolah rendah lagi. - Some of the metrics are blocked by yourconsent settings
Publication Preliminary assessment of Salvadora persica whitening effects on extracted stained teeth(Open Science Publishers LLP Inc., 2017) ;Nadia Halib ;Nabilah Bt Nuairy ;Haslinda Ramli ;Ishak Ahmad ;Norinsan Kamil Othman ;Salihatun Md Salleh ;Saiful Bahari Bakarudin ;Faculty of Dentistry ;Universiti Sains Islam Malaysia (USIM) ;Universiti Kebangsaan Malaysia (UKM)Universiti Tun Hussein Onn Malaysia (UTHM)The roots, twigs and stems of Salvadora persica (S. persica) also known as miswak have been used for centuries as oral hygiene tools. The cleansing efficacy of S. persica is thought to be attributed to the mechanical effects of its fibres. However, there is no study focus on S. persica whitening behaviour. Therefore, this study is conducted to preliminarily assess the whitening effects of S. persica on coffee and tea stained teeth. The bark of S. persica stems were peeled off and the pulps were dried and ground to produce powder. Scanning Electron Microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX) were carried out to study the properties of S. persica fibre. SEM revealed the presence of crystals of various shapes and sizes that act as natural abrasive agents and might contribute to its whitening effects while EDX identified that these minerals constitute of O (43.44 wt%), C (31.2 wt%), S (11.7 wt%), Ca (11.2 wt%), Na (1.3 wt%) and K (1.04 wt%). The powder later formulated into paste of various concentrations; 0.3%, 0.4%, 0.5% (w/w). Extracted permanent premolar teeth were cleaned and stained with tea and coffee solutions. Formulations of S. persica fiber paste were then used to brush the teeth and being compared to commercial whitening toothpaste. The teeth shade changes were evaluated using VITAPAN� Classical Shade. After brushing under standardized condition using a brushing simulator machine, it was found that the staining of teeth buccal surface was reduced at least one tone of shade according to the VitaPan� shade. � 2017 Nadia Halib et al. - Some of the metrics are blocked by yourconsent settings
Publication The remarkable three-dimensional network structure of bacterial cellulose for tissue engineering applications(Elsevier B.V., 2019) ;Nadia Halib ;Ishak Ahmad ;Mario Grassi ;Gabriele Grassi ;Faculty of Dentistry ;Universiti Sains Islam Malaysia (USIM) ;Universiti Kebangsaan Malaysia (UKM)Trieste UniversityCellulose is a natural homopolymer, composed of ?-1,4- anhydro-D-glucopyranose units. Unlike plant cellulose, bacterial cellulose (BC), obtained from species belonging to the genera of Acetobacter, Rhizobium, Agrobacterium, and Sarcina through various cultivation methods and techniques, is produced in its pure form. BC is produced in the form of gel-like, never dry sheet with tremendous mechanical properties. Containing up to 99% of water, BC hydrogel is considered biocompatible thus finding robust applications in the health industry. Moreover, BC three-dimensional structure closely resembles the extracellular matrix (ECM) of living tissue. In this review, we focus on the porous BC morphology particularly suited to host oxygen and nutrients thus providing conducive environment for cell growth and proliferation. The remarkable BC porous morphology makes this biological material a promising templet for the generation of 3D tissue culture and possibly for tissue-engineered scaffolds. � 2019 Elsevier B.V. - Some of the metrics are blocked by yourconsent settings
Publication Synthesis and characterization of thermo- and pH-responsive bacterial cellulose/acrylic acid hydrogels for drug delivery(Elsevier, 2012) ;Mohd Cairul Iqbal Mohd Amin ;Naveed Ahmad ;Nadia HalibIshak AhmadTo assist in identifying the utility of novel materials in drug-delivery applications, this study investigated the use of bacterial cellulose (BC), a natural biopolymer, in the synthesis of hydrogels for drug-delivery systems. BC was combined with different proportions of acrylic acid (AA) to fabricate hydrogels by exposure to accelerated electron-beam irradiation at different doses. Fourier transform infrared analysis revealed that the AA had been successfully grafted onto the cellulose fibers and allowed for prediction of the reaction mechanism in the synthesis of hydrogels. Thermal and morphological characterization indicated the formation of thermally stable hydrogels with pore size determined by AA content and irradiation dose. The results of swelling and in vitro drug-release studies revealed the hydrogels to be both thermo- and pH-responsive. Such thermo- and pH-responsiveness, in addition to their morphological characteristics, suggests that these BC/AA hydrogels are promising candidates as controlled drug-delivery systems. - Some of the metrics are blocked by yourconsent settings
Publication Unique Stimuli Responsive Characteristics Of Electron Beam Synthesized Bacterial Cellulose/acrylic Acid Composite(Wiley Periodicals, Inc., 2010) ;Nadia Halib ;Mohd Cairul Iqbal Mohd AminIshak AhmadThe formation and swelling behavior of bacterial cellulose/acrylic acid hydrogel prepared from aqueous mixture consists of 20 : 80 (v/v) acrylic acid (AAc) and 1% bacterial cellulose dispersion under accelerated electron beam was investigated. Gel fraction of hydrogel increased with the increasing dose suggesting a denser composite at 50 kGy compared to 35 kGy. SEM photomicrographs revealed a homogenous pores distribution at higher dose with pore sizes ranging from 1 to 5 μm. Hydrogel synthesized at lower dose of electron beam exhibited higher swelling ability and the degree of swelling increased as the pH of surrounding medium increased and it reached the optimum swelling at pH 7. While swelling of the hydrogel decreased with the increasing ionic strength of solution, swelling at different temperatures ranging from 25 to 50°C revealed a unique character where the hydrogel shrunk at 37°C. Moreover, hydrogel synthesized at higher dose exhibited a higher degree of swelling in methanol with respect to water. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010