Displaying publications 21 - 40 of 75 in total

Abstract:
Sort:
  1. Tabulation of organ dose conversion factors for terrestrial radioactivity monitoring program
    Sanusi MSM, Hassan WMSW, Hashim S, Ramli AT
    Appl Radiat Isot, 2021 Aug;174:109791.
    PMID: 34062400 DOI: 10.1016/j.apradiso.2021.109791
    Terrestrial radioactivity monitoring of 238U and 232Th series, and 40K in soil is an essential practice for radioactivity and radiation measurement of a place. In conventional practice, only basic data can be in-situ measured using a survey instrument, for example radioactivity concentration in soil and ambient dose equivalent rate. For other physical quantities, for example organ absorbed dose and organ equivalent dose, the measurement is impossible to be performed and can only be computed using Monte Carlo radiation transport simulations. In the past, most of the works only focused on calculating air-kerma-to-effective dose conversion factors. However, the information on organ dose conversion factors is scarcely documented and reported. This study was conducted to calculate organ absorbed and tissue-weighted equivalent dose conversion factors as a result of exposure from terrestrial gamma radiation. Series of organ dose conversion factors is produced based on computations from Monte Carlo MCNP5 simulations using modelled gamma irradiation geometry and established adult MIRD phantom. The study found out that most of the radiation exposed organs absorb energy at comparable rates, except for dense and superficial tissues i.e., skeleton and skin, which indicated slightly higher values. The good agreement between this work and previous studies demonstrated that our gamma irradiation geometry and modelling of gamma radiation sources are adequate. Therefore, the proposed organ dose conversion factors from this study are reasonably acceptable for dose estimation in environmental radioactivity monitoring practices.
  2. Synthesis, characterization, and morphology study of poly(acrylamide-co-acrylic acid)-grafted-poly(styrene-co-methyl methacrylate) "raspberry"-shape like structure microgels by pre-emulsified semi-batch emulsion polymerization
    Ramli RA, Hashim S, Laftah WA
    J Colloid Interface Sci, 2013 Feb 1;391:86-94.
    PMID: 23123033 DOI: 10.1016/j.jcis.2012.09.047
    A novel microgels were polymerized using styrene (St), methyl methacrylate (MMA), acrylamide (AAm), and acrylic acid (AAc) monomers in the presence of N,N'-methylenebisacrylamide (MBA) cross-linker. Pre-emulsified monomer was first prepared followed by polymerizing monomers using semi-batch emulsion polymerization. Fourier Transform Infrared Spectroscopy (FTIR) and (1)H Nuclear Magnetic Resonance (NMR) were used to determine the chemical structure and to indentify the related functional group. Grafting and cross-linking of poly(acrylamide-co-acrilic acid)-grafted-poly(styrene-co-methyl methacrylate) [poly(AAm-co-AAc)-g-poly(St-co-MMA)] microgels are approved by the disappearance of band at 1300 cm(-1), 1200 cm(-1) and 1163 cm(-1) of FTIR spectrum and the appearance of CH peaks at 5.5-5.7 ppm in (1)H NMR spectrum. Scanning Electron Microscope (SEM) images indicated that poly(St-co-MMA) particle was lobed morphology coated by cross-linked poly(AAm-co-AAc) shell. Furthermore, SEM results revealed that poly(AAm-co-AAc)-g-poly(St-co-MMA) is composite particle that consist of "raspberry"-shape like structure core. Internal structures of the microgels showed homogeneous network of pores, an extensive interconnection among pores, thicker pore walls, and open network structures. Water absorbency test indicated that the sample with particle size 0.43 μm had lower equilibrium water content, % than the sample with particle size 7.39 μm.
  3. Statistical relationship between activity concentrations of radionuclides 226Ra, 232Th, 40K, and 137Cs and geological formations in surface soil of Jordan
    Alomari AH, Saleh MA, Hashim S, Alsayaheen A, Abukashabeh A
    Isotopes Environ Health Stud, 2019 May;55(2):211-226.
    PMID: 30789050 DOI: 10.1080/10256016.2019.1581776
    An extensive study was conducted to determine the activity concentrations of natural and artificial radionuclides 226Ra, 232Th, 40K, and 137Cs in soil samples of each governate of Jordan. A total of 370 samples have been measured using a high-purity germanium detector. The activity concentration for 226Ra, 232Th, 40K, and 137Cs has mean values of 42 ± 3, 23 ± 3, 309 ± 21, and 3.7 ± 0.9 Bq kg-1, respectively. The highest mean activity concentration for 226Ra was found to be 138 ± 4 Bq kg-1 in the Alkarak governate. In the Ajloun and Jarash governates, the highest mean activity concentration was 35 ± 3 Bq kg-1 for 232Th, and 14.2 ± 1.9 Bq kg-1 for 137Cs, respectively. Geological influence on the activity concentrations was investigated using the one-way analysis of variance (ANOVA) and independent samples. The ANOVA results indicate that there are strong significant differences between the activity concentrations of 232Th, 40K, and 137Cs based on geological formations the radionuclides occur. The main contribution to gamma dose rate was due to 226Ra activity concentration. Radium equivalent and external hazard index are associated with a mean value of 98 Bq kg-1, and 0.266, respectively.
  4. Fulltext Spontaneous Haemothorax in a Patient with COVID-19
    Mohan SA, Fadzaily ZS, Abdullah Hashim SH
    Case Rep Med, 2022;2022:8275326.
    PMID: 35898334 DOI: 10.1155/2022/8275326
    The global pandemic of COVID-19 is caused by SARS-CoV-2 virus. We continue to discover the wide spectrum of complications associated with COVID-19. Some well-known complications include pneumonia, acute respiratory distress syndrome, pneumothorax, disseminated intravascular coagulation (DIC), chronic fatigue, multiorgan dysfunction, and long COVID-19 syndrome. We report a rare case of a 51-year-old man with severe COVID-19 pneumonia who developed haemorrhagic shock secondary to spontaneous haemothorax after 17 days of hospitalisation. Clinicians should be aware of such occurrence, and hence, high clinical suspicion, prompt recognition of signs and symptoms of shock, and adequate resuscitation will improve the outcomes of patients.
  5. Fulltext Soil gas radon and soil permeability assessment: Mapping radon risk areas in Perak State, Malaysia
    Nuhu H, Hashim S, Aziz Saleh M, Syazwan Mohd Sanusi M, Hussein Alomari A, Jamal MH, et al.
    PLoS One, 2021;16(7):e0254099.
    PMID: 34320010 DOI: 10.1371/journal.pone.0254099
    In this study geogenic radon potential (GRP) mapping was carried out on the bases of field radon in soil gas concentration and soil gas permeability measurements by considering the corresponding geological formations. The spatial pattern of soil gas radon concentration, soil permeability, and GRP and the relationship between geological formations and these parameters was studied by performing detailed spatial analysis. The radon activity concentration in soil gas ranged from 0.11 to 434.5 kBq m-3 with a mean of 18.96 kBq m-3, and a standard deviation was 55.38 kBq m-3. The soil gas permeability ranged from 5.2×10-14 to 5.2×10-12 m2, with a mean of 5.65×10-13 m2. The GRP values were computed from the 222Rn activity concentration and soil gas permeability data. The range of GRP values was from 0.04 to 154.08. Locations on igneous granite rock geology were characterized by higher soil radon gas activity and higher GRP, making them radon-prone areas according to international standards. The other study locations fall between the low to medium risk, except for areas with high soil permeability, which are not internationally classified as radon prone. A GRP map was created displaying radon-prone areas for the study location using Kriging/Cokriging, based on in situ and predicted measured values. The GRP map assists in human health risk assessment and risk reduction since it indicates the potential of the source of radon and can serve as a vital tool for radon combat planning.
  6. Fulltext Simple and efficient estimation of photovoltaic cells and modules parameters using approximation and correction technique
    Muhammad FF, Karim Sangawi AW, Hashim S, Ghoshal SK, Abdullah IK, Hameed SS
    PLoS One, 2019;14(5):e0216201.
    PMID: 31048867 DOI: 10.1371/journal.pone.0216201
    The behavior of solar cells and modules under various operational conditions can be determined effectively when their intrinsic parameters are accurately estimated and used to simulate the current-voltage (I-V) characteristics. This work proposed a new computational approach based on approximation and correction technique (ACT) for simple and efficient extraction of solar cells and modules parameters from the single-diode model. In this technique, an approximated value of series resistance (Rs) was first derived and used to determine the initial value of parallel resistance (Rp). Later, the final corrected values of Rs and Rp were obtained by resubstituting their approximated values in a five-loop iteration using the manipulated equations. For rapid evaluation and validation of the proposed technique, a software application was also created using MATLAB program. The correctness and robustness of the proposed technique was validated on five types of solar cells and modules operated at varied temperatures and irradiances. The lowest RMSE value was achieved for RTC France (7.78937E-4) and PVM 752 GaAs (2.10497E-4) solar cell. The legitimacy of ACT extracted parameters was established using a simple yet competitive implementation approach wherein the performance of the developed technique was compared with several state-of-the-art methods recently reported in the literature.
  7. SCATTER RADIATION IN THE FLUOROSCOPY-GUIDED INTERVENTIONAL ROOM
    Bohari A, Hashim S, Mohd Mustafa SN
    Radiat Prot Dosimetry, 2020 Jun 24;188(3):397-402.
    PMID: 31950168 DOI: 10.1093/rpd/ncz299
    Radiation scattered throughout the room during fluoroscopy-guided interventional (FGI) procedures was quantified at different locations using nanoDot optically stimulated luminescence dosemeters. All the tube angulation imaging shows that the radiation spectrum resembled a single peak distribution. The left anterior oblique 90° shows the highest single peak distribution (28.65 mSv/h). The single peak distribution for standard anteroposterior, left anterior oblique 45° and right anterior oblique 45° imaging was 13.32, 22.99 and 17.40 mSv/h, respectively. All tube angulation shows that the position of the interventional radiologist experienced a higher radiation level compared to other staffs. The doses of radiation varied widely around the perimeter of the patient's table and changed in accordance to imaging angles during procedures. Knowledge pertaining to radiation exposure levels is integral in order to avoid adverse risks, particularly among staff.
  8. Relationship between shear strength and soil water characteristic curve of an unsaturated granitic residual soil
    Huat, Bujang B.K, Faisal Ali, Hashim, S.
    Pertanika Journal of Science & Technology, 2007;15(2):113-120.
    MyJurnal
    The three shear strength parameters that are required to define a failure envelope of an unsaturated soil are c' (apparent cohesion),
  9. Regulatory requirements for nuclear power plant site selection in Malaysia-a review
    Basri NA, Hashim S, Ramli AT, Bradley DA, Hamzah K
    J Radiol Prot, 2016 Dec;36(4):R96-R111.
    PMID: 27631675
    Malaysia has initiated a range of pre-project activities in preparation for its planned nuclear power programme. Clearly one of the first steps is the selection of sites that are deemed suitable for the construction and operation of a nuclear power plant. Here we outline the Malaysian regulatory requirements for nuclear power plant site selection, emphasizing details of the selection procedures and site characteristics needed, with a clear focus on radiation safety and radiation protection in respect of the site surroundings. The Malaysia Atomic Energy Licensing Board (AELB) site selection guidelines are in accord with those provided in International Atomic Energy Agency (IAEA) and United Stated Nuclear Regulatory Commission (USNRC) documents. To enhance the suitability criteria during selection, as well as to assist in the final decision making process, possible assessments using the site selection characteristics and information are proposed.
  10. Fulltext Radiological hazard associated with amang processing industry in Peninsular Malaysia and its environmental impacts
    Sanusi MSM, Ramli AT, Hashim S, Lee MH
    Ecotoxicol Environ Saf, 2021 Jan 15;208:111727.
    PMID: 33396058 DOI: 10.1016/j.ecoenv.2020.111727
    Continuous depletion in tin productions has led to a newly emerging industry that is a tin by-product (amang) processing industry to harness mega tons of tin by-products produced in the past. Amang composed of profitable multi-heavy minerals and rare-earth elements. With poorly established safety and health practices in operating plant, amang poses extremely high radioactivity problem associated with high occupational ionizing radiation exposures to workers and continuously impacting the local environment with radioactive contamination from industrial effluent and solid waste into lithosphere and water bodies. The radioactivity level of 238U and 232Th series in the mineral varies from few hundreds up to ~200,000 and ~400,000 Bq kg-1 respectively and are potential to yield more than ~ 30,000 nGy h-1 of gamma (γ) radiation exposure to plant workers. The study found out that for 8 h of work time, a worker is estimated to receive an average effective dose of 0.1 mSv per day from external γ radiation source with a maximum up to 2 mSv per day for extreme exposure situation. Interferences of different exposure routes for examples inhalation of equivalent equilibrium concentration (ECC) of 222Rn and 220Rn progenies and airborne long-lived α particles from the dusty working environment could pose a higher total effective dose as much as 5 mSv per day and 115 mSv per year. The value is 5 times higher than the annual dose limit for designated radiation worker (20 mSv) in Peninsular Malaysia. The study found that 41% of the total received an effective dose received by a worker is contributed by 222Rn, 32% of airborne particulates and dust, 23% from external γ exposure and 4% from 220Rn. Based on radioecological risk assessment, the study found out that the aquatic environment is the highly exposed group to ionizing radiation from industrial effluent discharge and sand residues. With the impotent establishment of radiation protection in the industry, plus the country newly introduced long-term plan to revive tin mining as well as its accessory amang mineral, it is necessary for the government to harmonize current regulation to improve the worker safety and health as well as sustaining local environment.
  11. Radiological assessment subjected to outdoor radon and thoron concentrations and terrestrial gamma radiation measurements in Perak Malaysia
    Nuhu H, Hashim S, Mohd Sanusi MS, Mohammed Saleh MA
    Appl Radiat Isot, 2022 Jan;179:109991.
    PMID: 34710768 DOI: 10.1016/j.apradiso.2021.109991
    The concentrations of radon, thoron and terrestrial gamma radiation were measured to evaluate the outdoor effective dose. The outdoor radon activity concentration ranged from 5.79 to 5110 ± 46.36 Bq m-3, with a mean of 320.03 Bq m-3 which is higher than the EPA level of 14.8 Bq m-3. The range of the thoron activity concentration outdoor was from 0.00 to 4226.7 ± 58.5 Bq m-3, with a mean of 226.1 Bq m-3 which was above the UNSCEAR recommended level of 10 Bq m-3. The terrestrial gamma radiation dose rates range was from 98.31 to 3769.71 nGy h-1 with a mean of 446.27 nGy h-1. The effective dose contribution from radon exposures in the study was estimated to be 3.2 ± 0.5 mSv y-1 is about 84% total annual effective dose received by the population in those areas. The estimated thoron and gamma dose contributions (15%, and 1% respectively) were not significant. The outdoor doses for thoron and gamma were lower than the ICRP (2007) value of 1 mSv. The total annual outdoor effective dose with an occupancy factor of 1825 h (5 h day-1) was estimated to be within the range of 0.30-551.41 ± 0.65 mSv, with a mean of 3.75 mSv which is a little higher than the world average of 2.4 mSv.
  12. Fulltext Psychometric Properties of Malay Obsessive-compulsive Inventory-child Version (OCI-CV) in Malaysian Perspectives
    Fitri Sarnin E, Sharip S, Badilla Idris I, Mohd Hashim S, Salwina Wan Ismail W, Nazri Abdul Rahman F, et al.
    Scand J Child Adolesc Psychiatr Psychol, 2022 Jan;10(1):114-122.
    PMID: 36514488 DOI: 10.2478/sjcapp-2022-0012
    BACKGROUND: This study aimed to examine the psychometric properties of reliability and validity of OCI-CV in a non-clinical sample of Malaysian children and adolescents.

    METHOD: Participants of school-age and adolescent students from Klang Valley School completed the 21-item Malay OCI-CV using Google Form. OCI-CV English version was translated backward and forward to the Malay language. Face validity was conducted first before distributing the questionnaire to the participants. Exploratory Factor analysis (EFA) and Confirmatory Factor Analysis (CFA) was conducted to evaluate the psychometric properties of OCI-CV.

    RESULTS: A total of 102 school-age children and adolescents with a mean age of 15.96 years (male: 41.2%, female: 58.8%) participated in the study. The Malay OCI-CV showed high internal consistency, with Cronbach Alpha values of 0.90 for the whole scale. EFA showed multifactorial components. Five factors were labelled as "Washing / Ordering, Doubting, Obsessions, Checking, and Hoarding,". In the CFA, the five-factor model indicates adequate fit indices of (χ2/df = 1.51, RMSEA = .071, GFI = .824, AGFI = .769, NFI = .724, CFI = .880).

    CONCLUSION: The Malay OCI-CV has good psychometric properties and is suitable for use in the Malaysian context. Further validation studies should be conducted among a clinical population to enhance the generalization of this finding.

  13. Profile of poisoning admissions in Malaysia
    Rajasuriar R, Awang R, Hashim SB, Rahmat HR
    Hum Exp Toxicol, 2007 Feb;26(2):73-81.
    PMID: 17370864
    We retrospectively reviewed poisoning admissions to all government health facilities from 1999 to 2001, in an effort to expand our current knowledge on poisoning in Malaysia to a level that better reflects a nationwide burden. There were 21 714 admissions reported with 779 deaths. The case-fatality rate was 35.88/1000 admissions. The majority of admissions (89.7%) and deaths (98.9%) occurred in adults. Some 55.1% of all admissions were female, mostly involving pharmaceutical agents. Male poisoning admissions were more often due to chemical substances. The prevalence of poisoning and death was highest among Indians compared to all other races in Malaysia. Overall, the majority of poisoning admissions were due to pharmaceutical agents, with agents classified as non-opioid analgesics, anti-pyretics and anti-rheumatics the most common. Pesticides accounted for the largest number of fatalities. It was also the commonest substance reported in cases of intentional self-harm. Most cases of poisoning admissions occurred due to accidental exposure (47%), followed by cases of intentional self-harm (20.7%). Overall, this study has managed to contribute substantial additional information regarding the epidemiology of poisoning in Malaysia, highlighting important issues, such as the rampant poisonings involving pesticides and analgesics, as well as the high prevalence of poisoning among Indians in Malaysia.
  14. Prevalence of nosocomial infection and antibiotic use at a university medical center in Malaysia
    Hughes AJ, Ariffin N, Huat TL, Abdul Molok H, Hashim S, Sarijo J, et al.
    Infect Control Hosp Epidemiol, 2005 Jan;26(1):100-4.
    PMID: 15693416
    Most reports of nosocomial infection (NI) prevalence have come from developed countries with established infection control programs. In developing countries, infection control is often not as well established due to lack of staff and resources. We examined the rate of NI in our institution.
  15. Photon irradiation response of photonic crystal fibres and flat fibres at radiation therapy doses
    Hashim S, Ibrahim SA, Che Omar SS, Alajerami YS, Saripan MI, Noor NM, et al.
    Appl Radiat Isot, 2014 Aug;90:258-60.
    PMID: 24858954 DOI: 10.1016/j.apradiso.2014.04.016
    Radiation effects of photon irradiation in pure Photonic Crystal Fibres (PCF) and Flat fibres (FF) are still much less investigated in thermoluminescense dosimetry (TLD). We have reported the TL response of PCF and FF subjected to 6 MV photon irradiation. The proposed dosimeter shows good linearity at doses ranging from 1 to 4 Gy. The small size of these detectors points to its use as a dosimeter at megavoltage energies, where better tissue-equivalence and the Bragg-Gray cavity theory prevails.
  16. Photoluminescence and thermoluminescence properties of Li2 O-Na2 O-B2 O3 glass
    Razak NA, Hashim S, Mhareb MH, Tamchek N
    Luminescence, 2016 May;31(3):754-9.
    PMID: 26333749 DOI: 10.1002/bio.3020
    Influence of Nd(3+) concentration on the optical and thermoluminescence (TL) properties of melt-annealed synthesized 10 Na2 O: 20 Li2 O: (70-x) B2 O3 : xNd2 O3 , where 0.1≤ x ≤0.7 (LNB) glasses are determined. The absence of sharp peaks in X-ray diffraction patterns confirms the amorphous nature of the prepared glasses. The photoluminescence spectra under 800 nm laser excitations at room temperature exhibit three prominent peaks centred at 538, 603 and 675 nm corresponding to the transitions of (4) G7/2 → (4) I9/2 , [(4) G7/2 → (4) I11/2 , (4) G5/2 → (4) I9/2 ] and [(4) G7/2 → (4) I13/2 , (4) G5/2 → (4) I11/2 ], respectively. The TL glow curve exhibits a prominent peak (Tm ) at 180°C. The best performance of the prepared glass was found at 0.5 mol% of Nd2 O3 . We achieved a good linearity of TL response against dose between 0.5 to 4.0 Gy. The calculated value of the effective atomic number, Zeff , is 7.55 which is nearly tissue equivalent (Zeff = 7.42). These promising features demonstrate the capability of the aforementioned glass to be used as a radiation dosimeter. Copyright © 2015 John Wiley & Sons, Ltd.
  17. Fulltext Patients' perceptions of participation in educational home visits
    Jaffar A, Tan CE, Hamzah Z, Mohd Hashim S, Mohd Tohit N
    Educ Health (Abingdon), 2016;29(1):63-4.
    PMID: 26996805 DOI: 10.4103/1357-6283.178930
  18. Optically stimulated Al2O3:C luminescence dosimeters for teletherapy: Hp(10) performance evaluation
    Hashim S, Musa Y, Ghoshal SK, Ahmad NE, Hashim IH, Yusop M, et al.
    Appl Radiat Isot, 2018 May;135:7-11.
    PMID: 29353759 DOI: 10.1016/j.apradiso.2018.01.010
    The performance of optically stimulated luminescence dosimeters (OSLDs, Al2O3:C) was evaluated in terms of the operational quantity of HP(10) in Co-60 external beam teletherapy unit. The reproducibility, signal depletion, and dose linearity of each dosimeter was investigated. For ten repeated readouts, each dosimeter exposed to 50mSv was found to be reproducible below 1.9 ± 3% from the mean value, indicating good reader stability. Meanwhile, an average signal reduction of 0.5% per readout was found. The dose response revealed a good linearity within the dose range of 5-50mSv having nearly perfect regression line with R2 equals 0.9992. The accuracy of the measured doses were evaluated in terms of operational quantity HP(10), wherein the trumpet curve method was used respecting the 1990 International Commission on Radiological Protection (ICRP) standard. The accuracy of the overall measurements from all dosimeters was discerned to be within the trumpet curve and devoid of outlier. It is established that the achieved OSL Al2O3:C dosimeters are greatly reliable for equivalent dose assessment.
  19. Fulltext Naturally Occurring Radioactive Materials in Bracelets and Necklaces: Radiological Risk Evaluation
    Hassan HJ, Hashim S, Abu Hanifah NZH, Ghoshal SK, Sanusi MSM, Binti Suhailin FH, et al.
    Int J Environ Res Public Health, 2021 10 24;18(21).
    PMID: 34769689 DOI: 10.3390/ijerph182111170
    A particular category of jewelry is one involving bracelets and necklaces that are deliberately made to contain naturally occurring radioactive material (NORM)-purveyors making unsubstantiated claims for health benefits from the release of negative ions. Conversely, within the bounds of the linear no-threshold model, long-term use presents a radiological risk to wearers. Evaluation is conducted herein of the radiological risk arising from wearing these products and gamma-ray spectrometry is used to determine the radioactivity levels and annual effective dose of 15 commercially available bracelets (samples B1 to B15) and five necklaces (samples N16 to N20). Various use scenarios are considered; a Geant4 Monte Carlo (Geant4 MC) simulation is also performed to validate the experimental results. The dose conversion coefficient for external radiation and skin equivalent doses were also evaluated. Among the necklaces, sample N16 showed the greatest levels of radioactivity, at 246 ± 35, 1682 ± 118, and 221 ± 40 Bq, for 238U, 232Th, and 40K, respectively. For the bracelets, for 238U and 232Th, sample B15 displayed the greatest level of radioactivity, at 146 ± 21 and 980 ± 71 Bq, respectively. N16 offered the greatest percentage concentrations of U and Th, with means of 0.073 ± 0.0002% and 1.51 ± 0.0015%, respectively, giving rise to an estimated annual effective dose exposure of 1.22 mSv, substantially in excess of the ICRP recommended limit of 1 mSv/year.
  20. Montmorillonite-based polyacrylamide hydrogel rings for controlled vaginal drug delivery
    Sharifzadeh G, Hezaveh H, Muhamad II, Hashim S, Khairuddin N
    Mater Sci Eng C Mater Biol Appl, 2020 May;110:110609.
    PMID: 32204060 DOI: 10.1016/j.msec.2019.110609
    Vaginal drug delivery is regarded as a promising route against women-related health issues such as unwanted pregnancies and sexually transmitted infections. However, only a very few studies have been reported on the use of hydrogel rings with low cytotoxicity for vaginal drug delivery applications. Moreover, the effect of nanoparticles on hydrogel vaginal rings has not been clearly evaluated. To overcome these challenges, we hereby developed nanocomposite hydrogel rings based on polyacrylamide-sodium carboxymethyl cellulose-montmorillonite nanoparticles in the ring-shaped aluminum mold for controlled drug delivery. The hydrogel rings were synthesized by using N,N'-methylene bisacrylamide, N,N,N',N'-tetramethyl ethylene diamine, and ammonium persulfate, as a crosslinker, accelerator, and initiator, respectively. The obtained rings were 5.5 cm in diameters and 0.5 cm in rims. Chemical structures of the nanocomposite rings were confirmed by Fourier transform infrared, and Nuclear Magnetic Resonance spectroscopies. Additionally, the swelling ratio of hydrogels was appeared to be adjusted by the introduction of nanoparticles. In vitro release experiment of methylene blue, as a hydrophilic model drug, revealed that the nanocomposite rings could not only reduce burst effect (almost more than twice), but also achieve prolonged release for 15 days in the vaginal fluid simulant which mimic the vaginal conditions at pH of almost 4.2, and a temperature of 37 °C. Importantly, the resultant hydrogel rings with or without various concentrations of montmorillonite showed low cytotoxicity toward human skin fibroblasts. Furthermore, different antibacterial activities against Escherichia coli were observed for various concentrations of montmorillonite in hydrogels. These results suggest the great potential of montmorillonite-based hydrogel rings for vaginal drug delivery.
Related Terms
Filters
Contact Us

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

External Links