Displaying publications 1 - 20 of 154 in total

Abstract:
Sort:
  1. Yusoff N, Abu Osman NA, Pingguan-Murphy B
    Med Eng Phys, 2011 Jul;33(6):782-8.
    PMID: 21356602 DOI: 10.1016/j.medengphy.2011.01.013
    A mechanical-conditioning bioreactor has been developed to provide bi-axial loading to three-dimensional (3D) tissue constructs within a highly controlled environment. The computer-controlled bioreactor is capable of applying axial compressive and shear deformations, individually or simultaneously at various regimes of strain and frequency. The reliability and reproducibility of the system were verified through validation of the spatial and temporal accuracy of platen movement, which was maintained over the operating length of the system. In the presence of actual specimens, the system was verified to be able to deliver precise bi-axial load to the specimens, in which the deformation of every specimen was observed to be relatively homogeneous. The primary use of the bioreactor is in the culture of chondrocytes seeded within an agarose hydrogel while subjected to physiological compressive and shear deformation. The system has been designed specifically to permit the repeatable quantification and characterisation of the biosynthetic activity of cells in response to a wide range of short and long term multi-dimensional loading regimes.
  2. Ujang FA, Roslan AM, Osman NA, Norman A, Idris J, Farid MAA, et al.
    Sci Rep, 2021 Sep 14;11(1):18257.
    PMID: 34521938 DOI: 10.1038/s41598-021-97789-0
    The reason for such enormous efforts in palm oil mill effluent research would be what has been singled out as one of the major sources of pollution in Malaysia, and perhaps the most costly and complex waste to manage. Palm oil mill final discharge, which is the treated effluent, will usually be discharged to nearby land or river since it has been the least costly way to dispose of. Irrefutably, the quality level of the treated effluent does not always satisfy the surface water quality in conformity to physicochemical characteristics. To work on improving the treated effluent quality, a vertical surface-flow constructed wetland system was designed with Pennisetum purpureum (Napier grass) planted on the wetland floor. The system effectively reduced the level of chemical oxygen demand by 62.2 ± 14.3%, total suspended solid by 88.1 ± 13.3%, ammonia by 62.3 ± 24.8%, colour by 66.6 ± 13.19%, and tannin and lignin by 57.5 ± 22.3%. Heat map depicted bacterial diversity and relative abundance in life stages from the wetland soil, whereby bacterial community associated with the pollutant removal was found to be from the families Anaerolineaceae and Nitrosomonadaceae, and phyla Cyanobacteria and Acidobacteria.
  3. Tripathy A, Pramanik S, Cho J, Santhosh J, Osman NA
    Sensors (Basel), 2014;14(9):16343-422.
    PMID: 25256110 DOI: 10.3390/s140916343
    The humidity sensing characteristics of different sensing materials are important properties in order to monitor different products or events in a wide range of industrial sectors, research and development laboratories as well as daily life. The primary aim of this study is to compare the sensing characteristics, including impedance or resistance, capacitance, hysteresis, recovery and response times, and stability with respect to relative humidity, frequency, and temperature, of different materials. Various materials, including ceramics, semiconductors, and polymers, used for sensing relative humidity have been reviewed. Correlations of the different electrical characteristics of different doped sensor materials as the most unique feature of a material have been noted. The electrical properties of different sensor materials are found to change significantly with the morphological changes, doping concentration of different materials and film thickness of the substrate. Various applications and scopes are pointed out in the review article. We extensively reviewed almost all main kinds of relative humidity sensors and how their electrical characteristics vary with different doping concentrations, film thickness and basic sensing materials. Based on statistical tests, the zinc oxide-based sensing material is best for humidity sensor design since it shows extremely low hysteresis loss, minimum response and recovery times and excellent stability.
  4. Tripathy A, Pramanik S, Manna A, Shah NF, Shasmin HN, Radzi Z, et al.
    Sensors (Basel), 2016;16(3):292.
    PMID: 26927116 DOI: 10.3390/s16030292
    Armalcolite, a rare ceramic mineral and normally found in the lunar earth, was synthesized by solid-state step-sintering. The in situ phase-changed novel ceramic nanocrystals of Ca-Mg-Ti-Fe based oxide (CMTFOx), their chemical reactions and bonding with polydimethylsiloxane (PDMS) were determined by X-ray diffraction, infrared spectroscopy, and microscopy. Water absorption of all the CMTFOx was high. The lower dielectric loss tangent value (0.155 at 1 MHz) was obtained for the ceramic sintered at 1050 °C (S1050) and it became lowest for the S1050/PDMS nanocomposite (0.002 at 1 MHz) film, which was made by spin coating at 3000 rpm. The excellent flexibility (static modulus ≈ 0.27 MPa and elongation > 90%), viscoelastic property (tanδ = E″/E': 0.225) and glass transition temperature (Tg: -58.5 °C) were obtained for S1050/PDMS film. Parallel-plate capacitive and flexible resistive humidity sensors have been developed successfully. The best sensing performance of the present S1050 (3000%) and its flexible S1050/PDMS composite film (306%) based humidity sensors was found to be at 100 Hz, better than conventional materials.
  5. Tripathy A, Pramanik S, Manna A, Bhuyan S, Azrin Shah NF, Radzi Z, et al.
    Sensors (Basel), 2016 Jul 21;16(7).
    PMID: 27455263 DOI: 10.3390/s16071135
    Despite the many attractive potential uses of ceramic materials as humidity sensors, some unavoidable drawbacks, including toxicity, poor biocompatibility, long response and recovery times, low sensitivity and high hysteresis have stymied the use of these materials in advanced applications. Therefore, in present investigation, we developed a capacitive humidity sensor using lead-free Ca,Mg,Fe,Ti-Oxide (CMFTO)-based electro-ceramics with perovskite structures synthesized by solid-state step-sintering. This technique helps maintain the submicron size porous morphology of the developed lead-free CMFTO electro-ceramics while providing enhanced water physisorption behaviour. In comparison with conventional capacitive humidity sensors, the presented CMFTO-based humidity sensor shows a high sensitivity of up to 3000% compared to other materials, even at lower signal frequency. The best also shows a rapid response (14.5 s) and recovery (34.27 s), and very low hysteresis (3.2%) in a 33%-95% relative humidity range which are much lower values than those of existing conventional sensors. Therefore, CMFTO nano-electro-ceramics appear to be very promising materials for fabricating high-performance capacitive humidity sensors.
  6. Tripathy A, Pramanik S, Manna A, Shasmin HN, Radzi Z, Abu Osman NA
    Sensors (Basel), 2016 Nov 30;16(12).
    PMID: 27916913
    Since humidity sensors have been widely used in many sectors, a suitable humidity sensing material with improved sensitivity, faster response and recovery times, better stability and low hysteresis is necessary to be developed. Here, we fabricate a uniformly porous humidity sensor using Ca, Ti substituted Mg ferrites with chemical formula of CaMgFe1.33Ti₃O12 as humidity sensing materials by solid-sate step-sintering technique. This synthesis technique is useful to control the grain size with increased porosity to enhance the hydrophilic characteristics of the CaMgFe1.33Ti₃O12 nanoceramic based sintered electro-ceramic nanocomposites. The highest porosity, lowest density and excellent surface-hydrophilicity properties were obtained at 1050 °C sintered ceramic. The performance of this impedance type humidity sensor was evaluated by electrical characterizations using alternating current (AC) in the 33%-95% relative humidity (RH) range at 25 °C. Compared with existing conventional resistive humidity sensors, the present sintered electro-ceramic nanocomposite based humidity sensor showed faster response time (20 s) and recovery time (40 s). This newly developed sensor showed extremely high sensitivity (%S) and small hysteresis of <3.4%. Long-term stability of the sensor had been determined by testing for 30 consecutive days. Therefore, the high performance sensing behavior of the present electro-ceramic nanocomposites would be suitable for a potential use in advanced humidity sensors.
  7. Touri M, Moztarzadeh F, Abu Osman NA, Dehghan MM, Brouki Milan P, Farzad-Mohajeri S, et al.
    ACS Biomater Sci Eng, 2020 05 11;6(5):2985-2994.
    PMID: 33463293 DOI: 10.1021/acsbiomaterials.9b01789
    Hypoxia, the result of disrupted vasculature, can be categorized in the main limiting factors for fracture healing. A lack of oxygen can cause cell apoptosis, tissue necrosis, and late tissue healing. Remedying hypoxia by supplying additional oxygen will majorly accelerate bone healing. In this study, biphasic calcium phosphate (BCP) scaffolds were fabricated by robocasting, an additive manufacturing technique. Then, calcium peroxide (CPO) particles, as an oxygen-releasing agent, were coated on the BCP scaffolds. Segmental radial defects with the size of 15 mm were created in rabbits. Uncoated and CPO-coated BCP scaffolds were implanted in the defects. The empty (control) group received no implantation. Repairing of the bone was investigated via X-ray, histological analysis, and biomechanical tests at 3 and 6 months postoperatively, with immunohistochemical examinations at 6 months after operation. According to the radiological observations, formation of new bone was augmented at the interface between the implant and host bone and internal pores of CPO-coated BCP scaffolds compared to uncoated scaffolds. Histomorphometry analysis represented that the amount of newly formed bone in the CPO-coated scaffold was nearly two times higher than the uncoated one. Immunofluorescence staining revealed that osteogenic markers, osteonectin and octeocalcin, were overexpressed in the defects treated with the coated scaffolds at 6 months of postsurgery, demonstrating higher osteogenic differentiation and bone mineralization compared to the uncoated scaffold group. Furthermore, the coated scaffolds had superior biomechanical properties as in the case of 3 months after surgery, the maximal flexural force of the coated scaffolds reached to 134 N, while it was 92 N for uncoated scaffolds. The results could assure a boosted ability of bone repair for CPO-coated BCP scaffolds implanted in the segmental defect of rabbit radius because of oxygen-releasing coating, and this system of oxygen-generating coating/scaffold might be a potential for accelerated repairing of bone defects.
  8. Ting CY, Ahmad Zaidi Adruce S, Hassali MA, Ting H, Lim CJ, Ting RS, et al.
    Trials, 2018 Jun 05;19(1):310.
    PMID: 29871651 DOI: 10.1186/s13063-018-2649-9
    BACKGROUND: Amidst the high disease burden, non-adherence to medications among patients with type 2 diabetes mellitus (T2DM) has been reported to be common and devastating. Sarawak Pharmaceutical Services Division has formulated a pharmacist-led, multiple-theoretical-grounding, culturally sensitive and structured group-based program, namely "Know Your Medicine - Take if for Health" (MEDIHEALTH), to improve medication adherence among Malay patients with T2DM. However, to date, little is known about the effectiveness and sustainability of the Program.

    METHODS/DESIGN: This is a prospective, parallel-design, two-treatment-group randomized controlled trial to evaluate the effectiveness and sustainability of MEDIHEALTH in improving medication adherence. Malay patients who have underlying T2DM, who obtain medication therapy at Petra Jaya Health Clinic and Kota Samarahan Health Clinic, and who have a moderate to low adherence level (8-item Morisky Medication Adherence Scale, Malaysian specific, score <6) were randomly assigned to the treatment group (MEDIHEALTH) or the control group. The primary outcome of this study is medication adherence level at baseline and 1, 3, 6 and 12 months post-intervention. The secondary outcomes are attitude, subjective norms, perceived behavioural control, intention and knowledge related to medication adherence measured at baseline and 1, 6 and 12 months post-intervention. The effectiveness and sustainability of the Program will be triangulated by findings from semi-structured interviews with five selected participants conducted 1 month after the intervention and in-depth interviews with two main facilitators and two managerial officers in charge of the Program 12 months after the intervention. Statistical analyses of quantitative data were conducted using SPSS version 22 and Stata version 14. Thematic analysis for qualitative data were conducted with the assistance of ATLAS.ti 8.

    DISCUSSION: This study provides evidence on the effectiveness and sustainability of a structured group-based educational program that employs multiple theoretical grounding and a culturally sensitive approach in promoting medication adherence among Malays with underlying T2DM. Both the quantitative and qualitative findings of this study could assist in the future development of the Program.

    TRIAL REGISTRATION: National Medical Research Register, NMRR-17-925-35875 (IIR). Registered on 19 May 2017. ClinicalTrials.gov, NCT03228706 . Registered on 25 July 2017.

  9. Ting CY, Adruce SAZ, Hassali MA, Ting H, Lim CJ, Ting RS, et al.
    Trials, 2019 05 10;20(1):267.
    PMID: 31077233 DOI: 10.1186/s13063-019-3348-x
    After publication of the original article [1], the authors have notified us that there are changes to the primary outcome of the study, instrument, subject's inclusion criteria, the funding and acknowledgements. These changes were made during the recruitment of participants and after approved by the Medical Research and Ethics Committee (MREC), National Institutes of Health Malaysia, on 16th November 2018.
  10. Ting CY, Ahmad Zaidi Adruce S, Lim CJ, Abd Jabar AHA, Ting RS, Ting H, et al.
    Res Social Adm Pharm, 2021 02;17(2):344-355.
    PMID: 32327398 DOI: 10.1016/j.sapharm.2020.03.026
    BACKGROUND: A pharmacist-led structured group-based intervention (MEDIHEALTH) was formulated to improve medication adherence among Malay type 2 diabetes mellitus (T2DM) patients in the Malaysian state of Sarawak.

    OBJECTIVES: The objective of this study was to examine the effectiveness of MEDIHEALTH and its mechanism of impact for improving medication adherence and the glycated haemoglobin (HbA1c) level.

    METHODS: A two group and parallel randomised controlled trial with a twelve months follow-up period was conducted at two primary health clinics in Malaysia that were surrounded by Malay communities. Malay T2DM patients whose HbA1c was >7% and total score on the Self-Efficacy for Appropriate Medication Use Scale (SEAMS) was <26 were recruited and parallelly randomised to the MEDIHEALTH or usual care (control) groups. The extended theory of planned behaviour was employed to test the mechanism of impact. Repeated measure analysis of variance was used to assess the difference in the estimated marginal mean of the SEAMS scores and HbA1c level between the intervention and control groups at different times.

    RESULTS: A total of 142 participants were recruited and randomised; three from the intervention group and eight from the control group withdrew before receiving any treatment. Hence, 68 participants in the intervention group and 63 in the control group were included for analyses. The MEDIHEALTH group had a significantly greater increase in the SEAMS score compared to the control group (p 
  11. Ting CY, Abdul Halim NH, Ling JN, Tiong IK, Ahmad Shauki NIHJ, Lee YF, et al.
    BMC Geriatr, 2024 Feb 05;24(1):133.
    PMID: 38317117 DOI: 10.1186/s12877-024-04676-0
    BACKGROUND: The COVID-19 pandemic has fueled the widespread adoption of telemedicine in healthcare, particularly in Sarawak, Malaysia. This study investigates the use and acceptance of Sarawak's inaugural multidisciplinary geriatric telemedicine service, TELEG.

    METHODS: This cross-sectional study took place at the Sarawak Heart Centre's geriatric department from July 1, 2021, to April 30, 2022. Convenient sampling included all TELEG-enrolled patients during this period, to achieve minimum sample size of 148. TELEG's utilization was assessed in terms of medication therapy and treatment plan optimization, as well as enhanced healthcare accessibility. Participants' acceptance of TELEG was measured using the Service User Technology Acceptability Questionnaire (SUTAQ) administered through Google Forms. Descriptive statistics percentages illustrated the proportion of participants who found TELEG moderately to highly acceptable. Associations between baseline characteristics and overall acceptance were explored through bivariate analyses, including Pearson's correlation test, independent t-test, and ANOVA. The influence of six SUTAQ dimensions on overall acceptance, multivariable linear regression using enter method was employed. Statistical significance was determined by p-values less than 0.5.

    RESULTS: Among 180 geriatric patients enrolled in TELEG during the study period, 149 agreed to participate. TELEG led to medication therapy optimization for 88.6% of participants, primarily involving dose adjustment (44.7%), de-prescribing (31.8%), and prescribing (15.9%). Additionally, 53.8% received treatment plan optimization, predominantly in the form of self-care education (56.3%), referrals for further treatment (33.8%), additional laboratory investigations (29.6%), and increased monitoring (26.8%). Among those educated in self-care (n = 40), dietary intake (27.5%), lower limb exercise (25.0%), and COVID-19 vaccination (12.5%) were the most common topics. All participants expressed moderate to high acceptance of TELEG (mean = 4.9, SD = 0.65, on a scale of 1 to 6). Notably, care personnel concern (B = 0.256; p 

  12. Tham LK, Abu Osman NA, Wan Abas WA, Lim KS
    PLoS One, 2013;8(2):e55702.
    PMID: 23409022 DOI: 10.1371/journal.pone.0055702
    The deep tendon reflex assessments that are essential to the accurate diagnosis of neurological or neuromuscular disorders are conducted subjectively in clinical neurology. Our aim was to assess deep tendon reflexes objectively with a new reflex quantification method.
  13. Tham LK, Osman NA, Lim KS, Pingguan-Murphy B, Abas WA, Zain NM
    Med Eng Phys, 2011 May;33(4):407-10.
    PMID: 21146440 DOI: 10.1016/j.medengphy.2010.11.002
    The investigation of patellar tendon reflex involves development of a reflex hammer holder, kinematic data collection and analysis of patellar reflex responses using motion analysis techniques. The main aim of this research is to explore alternative means of assessing reflexes as a part of routine clinical diagnosis. The motion analysis system was applied to provide quantitative data which is a more objective measure of the patellar tendon reflex. Kinematic data was collected from 28 males and 22 females whilst subjected to a knee jerk test. Further analysis of kinematic data was performed to predict relationships which might affect the patellar tendon reflex. All subjects were seated on a high stool with their legs hanging freely within the capture volume of the motion analysis system. Knee jerk tests were applied to all subjects, on both sides of the leg, by eliciting hypo, hyper, and normal reflexes. An additional reinforcement technique called the Jendrassik manoeuvre was also performed under the same conditions to elicit a normal patellar tendon reflex. The comparison of reflex response between genders showed that female subjects generally had a greater response compared to males. However, the difference in reflex response between the left leg and the right leg was not significant. Tapping strength to elicit a hyper-reflex produced greater knee-jerk compared to the normal clinical tapping strength. All results were in agreement with clinical findings and results found by some early researchers.
  14. Tham LK, Al Kouzbary M, Al Kouzbary H, Liu J, Abu Osman NA
    Phys Eng Sci Med, 2023 Dec;46(4):1723-1739.
    PMID: 37870729 DOI: 10.1007/s13246-023-01332-6
    Assessment of the prosthetic gait is an important clinical approach to evaluate the quality and functionality of the prescribed lower limb prosthesis as well as to monitor rehabilitation progresses following limb amputation. Limited access to quantitative assessment tools generally affects the repeatability and consistency of prosthetic gait assessments in clinical practice. The rapidly developing wearable technology industry provides an alternative to objectively quantify prosthetic gait in the unconstrained environment. This study employs a neural network-based model in estimating three-dimensional body segmental orientation of the lower limb amputees during gait. Using a wearable system with inertial sensors attached to the lower limb segments, thirteen individuals with lower limb amputation performed two-minute walk tests on a robotic foot and a passive foot. The proposed model replicates features of a complementary filter to estimate drift free three-dimensional orientation of the intact and prosthetic limbs. The results indicate minimal estimation biases and high correlation, validating the ability of the proposed model to reproduce the properties of a complementary filter while avoiding the drawbacks, most notably in the transverse plane due to gravitational acceleration and magnetic disturbance. Results of this study also demonstrates the capability of the well-trained model to accurately estimate segmental orientation, regardless of amputation level, in different types of locomotion task.
  15. Syed M Haq AH, Md Yusof FA, Chan PL, Chok MCF, Phua GSY, Teoh CJ, et al.
    Curr Pharm Teach Learn, 2018 07;10(7):854-874.
    PMID: 30236423 DOI: 10.1016/j.cptl.2018.04.005
    BACKGROUND: The pharmacy internship program is designed to provide comprehensive training for interns to perform various roles in pharmacy practice. In Malaysia, the current internship program has been in place since 2004 in public health facilities, but has never been extensively evaluated.

    AIM: To assess the level of job satisfaction and perception of Provisionally Registered Pharmacists (PRP) towards the internship training provided.

    METHODS: A cross-sectional nationwide survey was conducted amongst all PRPs undergoing training between December 2015 and February 2016 to assess their level of job satisfaction and perception towards the training requirements stipulated by the Pharmacy Board of Malaysia.

    RESULTS: A total of 733 PRPs participated in the survey and the response rate was 95.8%. On the basis of the response received, 92.5% (n = 678) felt that the one year training period was 'just nice', 30.5% (n = 223) felt that the logbooks were 'too complicated', and 33.2% (n = 241) said the targets set by the Pharmacy Board of Malaysia were 'too high'. On a scale of 1 to 5, respondents rated 3.32 (SD 0.54) for mean score of job satisfaction. Significant factors influencing mean score of job satisfaction were: perceived fairness at the work place; perceived self-competence after one year of training; preceptors' competence; and pharmacy as a chosen career pathway.

    CONCLUSION: Intern pharmacists were fairly satisfied with the internship training in government facilities in the Ministry of Health, Malaysia. A review of the internship logbooks and the practicality of targets set by the Pharmacy Board warrant further improvement.

  16. Swarna Nantha Y, Kalasivan A, Ponnusamy Pillai M, Suppiah P, Md Sharif S, Krishnan SG, et al.
    Public Health Nutr, 2020 Feb;23(3):402-409.
    PMID: 31538554 DOI: 10.1017/S1368980019002684
    OBJECTIVE: The development of a second version of the Yale Food Addiction Scale (YFAS) coincides with the latest updates in the diagnosis of addiction as documented in the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders. The objective of the present study was to translate the YFAS 2.0 into the Malay language and test its psychometric properties in a primary-care population.

    DESIGN: Patients were assessed for food addiction utilizing the Malay YFAS 2.0. The participants were also assessed for eating disorder using the validated Malay Binge Eating Scale. The psychometric properties of the YFAS 2.0 were determined by analysing factor structure, overall item statistics, internal consistency and construct validity.

    SETTING: Between 2017 and 2018, participants were chosen from a regional primary-care clinic in the district of Seremban, Malaysia.

    PARTICIPANTS: Patients (n 382) from a regional primary-care clinic.

    RESULTS: The prevalence of food addiction was 5·0%. A two-factor structure of the YFAS was confirmed as the most optimal solution for the scale via confirmatory factor analysis. In both its diagnostic and symptom count version, the YFAS 2.0 had good internal consistency (Kuder-Richardson α > 0·80 and McDonald's ω > 0·9).

    CONCLUSIONS: We validated a psychometrically sound Malay version of the YFAS 2.0 in a primary-care population. Both diagnostic and symptom count versions of the scale had robust psychometric properties. The questionnaire can be used to develop health promotion strategies to detect food addiction tendencies in a general population.

  17. Sobh KNM, Abd Razak NA, Abu Osman NA
    Proc Inst Mech Eng H, 2021 Apr;235(4):419-427.
    PMID: 33517847 DOI: 10.1177/0954411920985753
    Electromyography signal has been used widely as input for prosthetic's leg movements. C-Leg, for example, is among the prosthetics devices that use electromyography as the main input. The main challenge facing the industrial party is the position of the electromyography sensor as it is fixed inside the socket. The study aims to investigate the best positional parameter of electromyography for transtibial prosthetic users for the device to be effective in multiple movement activities and compare with normal human muscle's activities. DELSYS Trigno wireless electromyography instrument was used in this study to achieve this aim. Ten non-amputee subjects and two transtibial amputees were involved in this study. The surface electromyography signals were recorded from two anterior and posterior below the knee muscles and above the knee muscles, respectively: tibial anterior and gastrocnemius lateral head as well as rectus femoris and biceps femoris during two activities (flexion and extension of knee joint and gait cycle for normal walking). The result during flexion and extension activities for gastrocnemius lateral head and biceps femoris muscles was found to be more useful for the control subjects, while the tibial anterior and also gastrocnemius lateral head are more active for amputee subjects. Also, during normal walking activity for biceps femoris and gastrocnemius lateral head, it was more useful for the control subjects, while for transtibial amputee subject-1, the rectus femoris was the highest signal of the average normal walking activity (0.0001 V) compared to biceps femoris (0.00007 V), as for transtibial amputee subject-2, the biceps femoris was the highest signals of the average normal walking activity (0.0001 V) compared to rectus femoris (0.00004 V). So, it is difficult to rely entirely on the static positioning of the electromyography sensor within the socket as there is a possibility of the sensor to contact with inactive muscle, which will be a gap in the control, leading to a decrease in the functional efficiency of the powered prostheses.
  18. Shirazi SF, Gharehkhani S, Mehrali M, Yarmand H, Metselaar HS, Adib Kadri N, et al.
    Sci Technol Adv Mater, 2015 Jun;16(3):033502.
    PMID: 27877783
    Since most starting materials for tissue engineering are in powder form, using powder-based additive manufacturing methods is attractive and practical. The principal point of employing additive manufacturing (AM) systems is to fabricate parts with arbitrary geometrical complexity with relatively minimal tooling cost and time. Selective laser sintering (SLS) and inkjet 3D printing (3DP) are two powerful and versatile AM techniques which are applicable to powder-based material systems. Hence, the latest state of knowledge available on the use of AM powder-based techniques in tissue engineering and their effect on mechanical and biological properties of fabricated tissues and scaffolds must be updated. Determining the effective setup of parameters, developing improved biocompatible/bioactive materials, and improving the mechanical/biological properties of laser sintered and 3D printed tissues are the three main concerns which have been investigated in this article.
  19. Shirazi FS, Mehrali M, Oshkour AA, Metselaar HS, Kadri NA, Abu Osman NA
    J Mech Behav Biomed Mater, 2014 Feb;30:168-75.
    PMID: 24316872 DOI: 10.1016/j.jmbbm.2013.10.024
    The focus of this study is to investigate the effect of Al2O3 on α-calcium silicate (α-CaSiO3) ceramic. α-CaSiO3 was synthesized from CaO and SiO2 using mechanochemical method followed by calcinations at 1000°C. α-CaSiO3 and alumina were grinded using ball mill to create mixtures, containing 0-50w% of Al2O3 loadings. The powders were uniaxially pressed and followed by cold isostatic pressing (CIP) in order to achieve greater uniformity of compaction and to increase the shape capability. Afterward, the compaction was sintered in a resistive element furnace at both 1150°C and 1250°C with a 5h holding time. It was found that alumina reacted with α-CaSiO3 and formed alumina-rich calcium aluminates after sintering. An addition of 15wt% of Al2O3 powder at 1250°C were found to improve the hardness and fracture toughness of the calcium silicate. It was also observed that the average grain sizes of α-CaSiO3 /Al2O3 composite were maintained 500-700nm after sintering process.
  20. Shafiei SS, Solati-Hashjin M, Samadikuchaksaraei A, Kalantarinejad R, Asadi-Eydivand M, Abu Osman NA
    PLoS One, 2015;10(8):e0136530.
    PMID: 26317853 DOI: 10.1371/journal.pone.0136530
    In recent years, nanotechnology in merging with biotechnology has been employed in the area of cancer management to overcome the challenges of chemopreventive strategies in order to gain promising results. Since most biological processes occur in nano scale, nanoparticles can act as carriers of certain drugs or agents to deliver it to specific cells or targets. In this study, we intercalated Epigallocatechin-3-Gallate (EGCG), the most abundant polyphenol in green tea, into Ca/Al-NO3 Layered double hydroxide (LDH) nanoparticles, and evaluated its efficacy compared to EGCG alone on PC3 cell line. The EGCG loaded LDH nanohybrids were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy (TEM) and nanosizer analyses. The anticancer activity of the EGCG-loaded LDH was investigated in prostate cancer cell line (PC3) while the release behavior of EGCG from LDH was observed at pH 7.45 and 4.25. Besides enhancing of apoptotic activity of EGCG, the results showed that intercalation of EGCG into LDH can improve the anti- tumor activity of EGCG over 5-fold dose advantages in in-vitro system. Subsequently, the in-vitro release data showed that EGCG-loaded LDH had longer release duration compared to physical mixture, and the mechanism of diffusion through the particle was rate-limiting step. Acidic attack was responsible for faster release of EGCG molecules from LDH at pH of 4.25 compared to pH of 7.4. The results showed that Ca/Al-LDH nanoparticles could be considered as an effective inorganic host matrix for the delivery of EGCG to PC3 cells with controlled release properties.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links