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  1. Fulltext Synthesis, characterization and fluorescent property evaluation of 1,3,5-triaryl-2-pyrazolines
    Hasan A, Abbas A, Akhtar MN
    Molecules, 2011 Sep 13;16(9):7789-802.
    PMID: 22143543 DOI: 10.3390/molecules16097789
    A series of 1,3,5-triaryl-2-pyrazolines was synthesized by dissolving the corresponding 4-alkoxychalcones in glacial acetic acid containing a few drops of concentrated hydrochloric acid. This step was followed by the addition of (3,4-dimethylphenyl) hydrazaine hydrochloride. Finally the target compounds were precipitated by pouring the reaction mixture onto crushed ice. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The 1,3,5-triaryl-2-pyrazolines bearing homologous alkoxy groups were found to possess fluorescence properties in the blue region of the visible spectrum when irradiated with ultraviolet radiation. The fluorescent behavior of these compounds was studied by UV-Vis and emission spectroscopy, performed at room temperature.
  2. Fulltext Synthesis, characterization and antifungal evaluation of 5-substituted-4-amino-1,2,4-triazole-3-thioesters
    Hasan A, Thomas NF, Gapil S
    Molecules, 2011;16(2):1297-309.
    PMID: 21278680 DOI: 10.3390/molecules16021297
    A series of 5-substituted-4-amino-1,2,4-triazole-3-thioesters was synthesized by converting variously substituted organic acids successively into the corresponding esters, hydrazides, 5-substituted-1,3,4-oxadiazole-2-thiols, 5-substituted-1,2,4-triazole-2-thiols and 5-substituted-1,3,4-oxadiazole-2-thioesters. Finally the target compounds were obtained by refluxing 5-substituted-1,3,4-oxadiazole-2-thioesters in the presence of hydrazine hydrate and absolute alcohol. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The synthesized compounds were evaluated for their in vitro antifungal activity. Some of the evaluated compounds possessed significant antifungal activity as compared to a terbinafine standard.
  3. Fulltext Application of reinforcement learning in cognitive radio networks: models and algorithms
    Yau KL, Poh GS, Chien SF, Al-Rawi HA
    ScientificWorldJournal, 2014;2014:209810.
    PMID: 24995352 DOI: 10.1155/2014/209810
    Cognitive radio (CR) enables unlicensed users to exploit the underutilized spectrum in licensed spectrum whilst minimizing interference to licensed users. Reinforcement learning (RL), which is an artificial intelligence approach, has been applied to enable each unlicensed user to observe and carry out optimal actions for performance enhancement in a wide range of schemes in CR, such as dynamic channel selection and channel sensing. This paper presents new discussions of RL in the context of CR networks. It provides an extensive review on how most schemes have been approached using the traditional and enhanced RL algorithms through state, action, and reward representations. Examples of the enhancements on RL, which do not appear in the traditional RL approach, are rules and cooperative learning. This paper also reviews performance enhancements brought about by the RL algorithms and open issues. This paper aims to establish a foundation in order to spark new research interests in this area. Our discussion has been presented in a tutorial manner so that it is comprehensive to readers outside the specialty of RL and CR.
  4. Fulltext Reinforcement learning for routing in cognitive radio ad hoc networks
    Al-Rawi HA, Yau KL, Mohamad H, Ramli N, Hashim W
    ScientificWorldJournal, 2014;2014:960584.
    PMID: 25140350 DOI: 10.1155/2014/960584
    Cognitive radio (CR) enables unlicensed users (or secondary users, SUs) to sense for and exploit underutilized licensed spectrum owned by the licensed users (or primary users, PUs). Reinforcement learning (RL) is an artificial intelligence approach that enables a node to observe, learn, and make appropriate decisions on action selection in order to maximize network performance. Routing enables a source node to search for a least-cost route to its destination node. While there have been increasing efforts to enhance the traditional RL approach for routing in wireless networks, this research area remains largely unexplored in the domain of routing in CR networks. This paper applies RL in routing and investigates the effects of various features of RL (i.e., reward function, exploitation, and exploration, as well as learning rate) through simulation. New approaches and recommendations are proposed to enhance the features in order to improve the network performance brought about by RL to routing. Simulation results show that the RL parameters of the reward function, exploitation, and exploration, as well as learning rate, must be well regulated, and the new approaches proposed in this paper improves SUs' network performance without significantly jeopardizing PUs' network performance, specifically SUs' interference to PUs.
  5. Fulltext Plasmodium knowlesi malaria in humans is widely distributed and potentially life threatening
    Cox-Singh J, Davis TM, Lee KS, Shamsul SS, Matusop A, Ratnam S, et al.
    Clin Infect Dis, 2008 Jan 15;46(2):165-71.
    PMID: 18171245 DOI: 10.1086/524888
    BACKGROUND: Until recently, Plasmodium knowlesi malaria in humans was misdiagnosed as Plasmodium malariae malaria. The objectives of the present study were to determine the geographic distribution of P. knowlesi malaria in the human population in Malaysia and to investigate 4 suspected fatal cases.

    METHODS: Sensitive and specific nested polymerase chain reaction was used to identify all Plasmodium species present in (1) blood samples obtained from 960 patients with malaria who were hospitalized in Sarawak, Malaysian Borneo, during 2001-2006; (2) 54 P. malariae archival blood films from 15 districts in Sabah, Malaysian Borneo (during 2003-2005), and 4 districts in Pahang, Peninsular Malaysia (during 2004-2005); and (3) 4 patients whose suspected cause of death was P. knowlesi malaria. For the 4 latter cases, available clinical and laboratory data were reviewed.

    RESULTS: P. knowlesi DNA was detected in 266 (27.7%) of 960 of the samples from Sarawak hospitals, 41 (83.7%) of 49 from Sabah, and all 5 from Pahang. Only P. knowlesi DNA was detected in archival blood films from the 4 patients who died. All were hyperparasitemic and developed marked hepatorenal dysfunction.

    CONCLUSIONS: Human infection with P. knowlesi, commonly misidentified as the more benign P. malariae, are widely distributed across Malaysian Borneo and extend to Peninsular Malaysia. Because P. knowlesi replicates every 24 h, rapid diagnosis and prompt effective treatment are essential. In the absence of a specific routine diagnostic test for P. knowlesi malaria, we recommend that patients who reside in or have traveled to Southeast Asia and who have received a "P. malariae" hyperparasitemia diagnosis by microscopy receive intensive management as appropriate for severe falciparum malaria.

  6. Fulltext Increasing incidence of Plasmodium knowlesi malaria following control of P. falciparum and P. vivax Malaria in Sabah, Malaysia
    William T, Rahman HA, Jelip J, Ibrahim MY, Menon J, Grigg MJ, et al.
    PLoS Negl Trop Dis, 2013;7(1):e2026.
    PMID: 23359830 DOI: 10.1371/journal.pntd.0002026
    BACKGROUND: The simian parasite Plasmodium knowlesi is a common cause of human malaria in Malaysian Borneo and threatens the prospect of malaria elimination. However, little is known about the emergence of P. knowlesi, particularly in Sabah. We reviewed Sabah Department of Health records to investigate the trend of each malaria species over time.

    METHODS: Reporting of microscopy-diagnosed malaria cases in Sabah is mandatory. We reviewed all available Department of Health malaria notification records from 1992-2011. Notifications of P. malariae and P. knowlesi were considered as a single group due to microscopic near-identity.

    RESULTS: From 1992-2011 total malaria notifications decreased dramatically, with P. falciparum peaking at 33,153 in 1994 and decreasing 55-fold to 605 in 2011, and P. vivax peaking at 15,857 in 1995 and decreasing 25-fold to 628 in 2011. Notifications of P. malariae/P. knowlesi also demonstrated a peak in the mid-1990s (614 in 1994) before decreasing to ≈ 100/year in the late 1990s/early 2000s. However, P. malariae/P. knowlesi notifications increased >10-fold between 2004 (n = 59) and 2011 (n = 703). In 1992 P. falciparum, P. vivax and P. malariae/P. knowlesi monoinfections accounted for 70%, 24% and 1% respectively of malaria notifications, compared to 30%, 31% and 35% in 2011. The increase in P. malariae/P. knowlesi notifications occurred state-wide, appearing to have begun in the southwest and progressed north-easterly.

    CONCLUSIONS: A significant recent increase has occurred in P. knowlesi notifications following reduced transmission of the human Plasmodium species, and this trend threatens malaria elimination. Determination of transmission dynamics and risk factors for knowlesi malaria is required to guide measures to control this rising incidence.

  7. Synthesis, spectral characterization, self-assembly and biological studies of N-acyl-2-pyrazolines bearing long alkoxy side chains
    Abbas A, Nazir H, Naseer MM, Bolte M, Hussain S, Hafeez N, et al.
    Spectrochim Acta A Mol Biomol Spectrosc, 2014;120:176-84.
    PMID: 24177882 DOI: 10.1016/j.saa.2013.10.023
    A series of new pyrazoline derivatives (1b-4c) bearing N-acyl arms and nine to twelve carbon long alkoxy side chains was synthesized and characterized on the basis of spectroscopic data and microanalysis. The nature of self-assembly to understand the interplay of alkoxy chain crystallization and various supramolecular interactions was investigated using single crystal X-ray diffraction studies. Interesting self-assembled supramolecular structures of 1b and 4c were observed in the crystal lattice owing to various CH⋯O, H⋯H, CH⋯π, lonepair⋯π and π⋯π interactions. Further, all the synthesized compounds (1b-4c) were screened for their in vitro antifungal and anti-inflammatory activities. Compounds 2b, 3b, 2c and 3c showed significant to moderate antifungal activity against Microsporum canis whereas most of the other compounds were found inactive against all the five tested fungal strains. Good anti-inflammatory activity was observed for compounds 1b with IC50 value 331 μM compared to 273 μM for Indomethacine, a standard reference drug. The bio-activity data demonstrates the relationship between lipophilicity, solubility and bioavailability.
  8. Natural halloysite nanotubes /chitosan based bio-nanocomposite for delivering norfloxacin, an anti-microbial agent in sustained release manner
    Barman M, Mahmood S, Augustine R, Hasan A, Thomas S, Ghosal K
    Int J Biol Macromol, 2020 Nov 01;162:1849-1861.
    PMID: 32781129 DOI: 10.1016/j.ijbiomac.2020.08.060
    Applying nanotechnology to deliver drug could result in several benefits such as prolong duration of action, enhancement in overall bioavailability, targeting to specific site, low initial loading dose require, systemic stability enhancement etc. Halloysite is one of those clay minerals showing maximum effectiveness when consider as a nano drug carriers for different kind applications. Here, we have used norfloxacin as the model drug for loading into halloysite nanotube (HNT) for its anti-bacterial activity. Norfloxacin was loaded into halloysites by vacuum operation and sonication. The nanotubes were evaluated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), optical microscopy, water absorption studies, cytotoxicity studies, antimicrobial studies and in vitro diffusion studies. SEM, FT-IR and XRD analysis data showed that the norfloxacin was successfully loaded into nanotubes. TEM analysis confirmed loading of norfloxacin in halloysites' lumen. The halloysite/chitosan nanocomposites were prepared by solvent casting and freeze-drying method. SEM analysis revealed compact and rugged surface of nanocomposites due to existing norfloxacin loaded halloysite. FTIR and XRD confirmed formation of nanocomposite. The nanocomposites showed good antimicrobial effect and good biocompatibility in cytotoxicity study. The in-vitro release studies revealed that halloysite/chitosan nanocomposites were able to sustain the drug release. Also, the nanocomposites were stable in various humidity conditions. Therefore, all the outcomes suggest that the prepared nanocomposites can provide enhanced therapeutic benefits and they can be very potential nano vehicle for sustaining drug delivery.
  9. In silico screening of Allium cepa phytochemicals for their binding abilities to SARS and SARS-CoV-2 3C-like protease and COVID-19 human receptor ACE-2
    Bondhon TA, Fatima A, Jannat K, Hasan A, Jahan R, Nissapatorn V, et al.
    Trop Biomed, 2021 Jun 01;38(2):214-221.
    PMID: 34172713 DOI: 10.47665/tb.38.2.060
    Corona virus SARS-CoV-2-induced viral disease (COVID-19) is a zoonotic disease that was initially transmitted from animals to humans. The virus surfaced towards the end of December 2019 in Wuhan, China where earlier SARS (Severe Acute Respiratory Syndrome) had also surfaced in 2003. Unlike SARS, SARS-CoV-2 (a close relative of the SARS virus) created a pandemic, and as of February 24 2021, caused 112,778,672 infections and 2,499,252 deaths world-wide. Despite the best efforts of scientists, no drugs against COVID-19 are yet in sight; five vaccines have received emergency approval in various countries, but it would be a difficult task to vaccinate twice the world population of 8 billion. The objective of the present study was to evaluate through in silico screening a number of phytochemicals in Allium cepa (onion) regarding their ability to bind to the main protease of COVID-19 known as the 3C-like protease or 3CLpro, (PDB ID: 6LU7), 3CLpro of SARS (PDB ID: 3M3V), and human angiotensin converting enzyme-2 (ACE-2), [PDB ID: 1R42], which functions as a receptor for entry of the virus into humans. Molecular docking (blind docking, that is docking not only against any target pocket) were done with the help of AutoDockVina. It was observed that of the twenty-two phytochemicals screened, twelve showed good binding affinities to the main protease of SARS-CoV-2. Surprisingly, the compounds also demonstrated good binding affinities to ACE-2. It is therefore very likely that the binding affinities shown by these compounds against both 3CLpro and ACE-2 merit further study for their potential use as therapeutic agents.
  10. Potential role of flavonoids against SARS-CoV-2 induced diarrhea
    Paul AK, Jahan R, Bondhon TA, Jannat K, Hasan A, Rahmatullah M, et al.
    Trop Biomed, 2021 Sep 01;38(3):360-365.
    PMID: 34508344 DOI: 10.47665/tb.38.3.079
    COVID-19, caused by the SARS-CoV-2 virus, can lead to massive inflammation in the gastrointestinal tract causing severe clinical symptoms. SARS-CoV-2 infects lungs after binding its spike proteins with alveolar angiotensin-converting enzyme 2 (ACE2), and it also triggers inflammation in the gastrointestinal tract. SARS-CoV-2 invades the gastrointestinal tract by interacting with Toll-like receptor-4 (TLR4) that induces the expression of ACE2. The influx of ACE2 facilitates cellular binding of more SARS-CoV-2 and causes massive gastrointestinal inflammation leading to diarrhea. Diarrhea prior to COVID-19 infection or COVID-19-induced diarrhea reportedly ends up in a poor prognosis for the patient. Flavonoids are part of traditional remedies for gastrointestinal disorders. Preclinical studies show that flavonoids can prevent infectious diarrhea. Recent studies show flavonoids can inhibit the multiplication of SARS-CoV-2. In combination with vitamin D, flavonoids possibly activate nuclear factor erythroid-derived-2-related factor 2 that downregulates ACE2 expression in cells. We suggest that flavonoids have the potential to prevent SARS-CoV-2 induced diarrhea.
  11. Bioactive scaffold (sodium alginate)-g-(nHAp@SiO2@GO) for bone tissue engineering
    Khan MUA, Razak SIA, Rehman S, Hasan A, Qureshi S, Stojanović GM
    Int J Biol Macromol, 2022 Dec 01;222(Pt A):462-472.
    PMID: 36155784 DOI: 10.1016/j.ijbiomac.2022.09.153
    Globally, people suffering from bone disorders are steadily increasing and bone tissue engineering is an advanced approach to treating fractured and defected bone tissues. In this study, we have prepared polymeric nanocomposite by free-radical polymerization from sodium alginate, hydroxyapatite, and silica with different GO amounts. The porous scaffolds were fabricated using the freeze drying technique. The structural, morphological, mechanical, and wetting investigation was conducted by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, universal tensile machine, and water contact angle characterization techniques. The swelling, biodegradation, and water retention were also studied. The biological studies were performed (cell viability, cell adherence, proliferation, and mineralization) against osteoblast cell lines. Scaffolds have exhibited different pore morphology SAG-1 (pore size = 414.61 ± 56 μm and porosity = 81.45 ± 2.17 %) and SAG-4 (pore size = 195.97 ± 82 μm and porosity = 53.82 ± 2.45 %). They have different mechanical behavior as SAG-1 has the least compression strength and compression modulus 2.14 ± 2.35 and 16.51 ± 1.27 MPa. However, SAG-4 has maximum compression strength and compression modulus 13.67 ± 2.63 and 96.16 ± 1.97 MPa with wetting behavior 80.70° and 58.70°, respectively. Similarly, SAG-1 exhibited the least and SAG-4 presented maximum apatite mineral formation, cell adherence, cell viability, and cell proliferation against mouse pre-osteoblast cell lines. The increased GO amount provides different multifunctional materials with different characteristics. Hence, the fabricated scaffolds could be potential scaffold materials to treat and regenerate fracture bone tissues in bone tissue engineering.
  12. Can Costus afer be used for co-treatment of COVID-19, its symptoms and comorbidities? A novel approach for combating the pandemic and implications for sub-Saharan Africa
    Jannat K, Hasan A, Bondhon TA, Mahboob T, Paul AK, Jahan R, et al.
    Trop Biomed, 2021 Dec 01;38(4):540-551.
    PMID: 35001920 DOI: 10.47665/tb.38.4.097
    Despite the huge loss of lives and massive disruption of the world economy by the COVID -19 pandemic caused by SARS -CoV-2, scientists are yet to come out with an effective therapeutic against this viral disease . Several vaccines have obtained 'emergency approval ', but difficulties are being faced in the even distribution of vaccines amongst high- and low- income countries . On top of it, comorbidities associated with COVID -19 like diabetes, hypertension and malaria can seriously impede the treatment of the main disease, thus increasing the fatality rate . This is more so in the context of sub -Saharan African and south Asian countries . Our objective was to demonstrate that a single plant containing different phytoconstituents may be used for treatment of COVID -19 and comorbidities . Towards initial selection of a plant, existing scientific literature was scanned for reported relevant traditional uses, phytochemicals and pharmacological activities of a number of plants and their phytoconstituents pertaining to treatment of COVID-19 symptoms and comorbidities. Molecular docking studies were then performed with phytochemicals of the selected plant and SARS-CoV-2 components - Mpro, and spike protein receptor binding domain and hACE2 interface using AutoDock V ina. We showed that crude extracts of an indigenous African plant, Costus afer having traditional antidiabetic and antimalarial uses, has phytochemicals with high binding affinities for Mpro, and /or spike protein receptor binding domain and hACE2 interface; the various phytochemicals with predicted high binding energies include aferoside C, dibutyl phthalate, nerolidol, suginal, and ± -terpinene, making them potential therapeutics for COVID -19. The results suggest that crude extracts and phytochemicals of C. afer can function as a treatment modality for COVID -19 and comorbidities like especially diabetes and malaria .
  13. Fulltext Phytochemical-assisted green synthesis of CuFeOx nano-rose electrocatalysts for oxygen evolution reaction in alkaline media
    Sarkar DK, Selvanathan V, Mottakin M, Hasan AKM, Islam MA, Almohamadi H, et al.
    RSC Adv, 2023 Jun 22;13(28):19130-19139.
    PMID: 37362330 DOI: 10.1039/d3ra02512h
    This study represents a green synthesis method for fabricating an oxygen evolution reaction (OER) electrode by depositing two-dimensional CuFeOx on nickel foam (NF). Two-dimensional CuFeOx was deposited on NF using in situ hydrothermal synthesis in the presence of Aloe vera extract. This phytochemical-assisted synthesis of CuFeOx resulted in a unique nano-rose-like morphology (petal diameter 30-70 nm), which significantly improved the electrochemical surface area of the electrode. The synthesized electrode was analyzed for its OER electrocatalytic activity and it was observed that using 75% Aloe vera extract in the phytochemical-assisted synthesis of CuFeOx resulted in improved OER electrocatalytic performance by attaining an overpotential of 310 mV for 50 mA cm-2 and 410 mV for 100 mA cm-2. The electrode also sustained robust stability throughout the 50 h of chronopotentiometry studies under alkaline electrolyte conditions, demonstrating its potential as an efficient OER electrode material. This study highlights the promising use of Aloe vera extract as a green and cost-effective way to synthesize efficient OER electrode materials.
  14. Fulltext Graphene Oxide-Functionalized Bacterial Cellulose-Gelatin Hydrogel with Curcumin Release and Kinetics: In Vitro Biological Evaluation
    Khan MUA, Stojanović GM, Rehman RA, Moradi AR, Rizwan M, Ashammakhi N, et al.
    ACS Omega, 2023 Oct 31;8(43):40024-40035.
    PMID: 37929099 DOI: 10.1021/acsomega.2c06825
    Biopolymer-based bioactive hydrogels are excellent wound dressing materials for wound healing applications. They have excellent properties, including hydrophilicity, tunable mechanical and morphological properties, controllable functionality, biodegradability, and desirable biocompatibility. The bioactive hydrogels were fabricated from bacterial cellulose (BC), gelatin, and graphene oxide (GO). The GO-functionalized-BC (GO-f-BC) was synthesized by a hydrothermal method and chemically crosslinked with bacterial cellulose and gelatin using tetraethyl orthosilicate (TEOS) as a crosslinker. The structural, morphological, and wettability properties were studied using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and a universal testing machine (UTM), respectively. The swelling analysis was conducted in different media, and aqueous medium exhibited maximum hydrogel swelling compared to other media. The Franz diffusion method was used to study curcumin (Cur) release (Max = 69.32%, Min = 49.32%), and Cur release kinetics followed the Hixson-Crowell model. Fibroblast (3T3) cell lines were employed to determine the cell viability and proliferation to bioactive hydrogels. Antibacterial activities of bioactive hydrogels were evaluated against infection-causing bacterial strains. Bioactive hydrogels are hemocompatible due to their less than 0.5% hemolysis against fresh human blood. The results show that bioactive hydrogels can be potential wound dressing materials for wound healing applications.
  15. Fabrication of amine-functionalized and multi-layered PAN-(TiO2)-gelatin nanofibrous wound dressing: In-vitro evaluation
    Khan R, Haider S, Khan MUA, Haider A, Razak SIA, Hasan A, et al.
    Int J Biol Macromol, 2023 Dec 31;253(Pt 5):127169.
    PMID: 37783243 DOI: 10.1016/j.ijbiomac.2023.127169
    The development of advanced multifunctional wound dressings remains a major challenge. Herein, a novel multilayer (ML) electrospun nanofibers (NFs) wound dressing based on diethylenetriamine (DETA) functionalized polyacrylonitrile (PAN), TiO2 nanoparticles (NPs) coating (Ct), and bioderived gelatin (Gel) was developed for potential applications in wound healing. The ML PAN-DETA-Ct-Gel membrane was developed by combining electrospinning, chemical functionalization, synthesis, and electrospray techniques, using a layer-by-layer method. The ML PAN-DETA-Ct-Gel membrane is comprised of an outer layer of PAN-DETA as a barrier to external microorganisms and structural support, an interlayer TiO2 NPs (Ct) as antibacterial function, and a contact layer (Gel) to improve biocompatibility and cell viability. The NFs membranes were characterized by scanning electron microscopy (SEM), surface profilometry, BET analysis, and water contact angle techniques to investigate their morphology, surface roughness, porosity, and wettability. The ML PAN-DETA-Ct-Gel wound dressing exhibited good surface roughness, porosity, and better wettability. Cell morphology, proliferation, and viability were determined using fibroblasts (3T3), and antibacterial assays were performed against six pathogens. The ML PAN-DETA-Ct-Gel NFs membrane showed good cell morphology, proliferation, viability, and antibacterial activity compared with other membranes. This new class of ML NFs membranes offers a multifunctional architecture with adequate biocompatibility, cell viability, and antibacterial activity.
  16. Fundamental properties of smart hydrogels for tissue engineering applications: A review
    Khan MUA, Stojanović GM, Abdullah MFB, Dolatshahi-Pirouz A, Marei HE, Ashammakhi N, et al.
    Int J Biol Macromol, 2024 Jan;254(Pt 3):127882.
    PMID: 37951446 DOI: 10.1016/j.ijbiomac.2023.127882
    Tissue engineering is an advanced and potential biomedical approach to treat patients suffering from lost or failed an organ or tissue to repair and regenerate damaged tissues that increase life expectancy. The biopolymers have been used to fabricate smart hydrogels to repair damaged tissue as they imitate the extracellular matrix (ECM) with intricate structural and functional characteristics. These hydrogels offer desired and controllable qualities, such as tunable mechanical stiffness and strength, inherent adaptability and biocompatibility, swellability, and biodegradability, all crucial for tissue engineering. Smart hydrogels provide a superior cellular environment for tissue engineering, enabling the generation of cutting-edge synthetic tissues due to their special qualities, such as stimuli sensitivity and reactivity. Numerous review articles have presented the exceptional potential of hydrogels for various biomedical applications, including drug delivery, regenerative medicine, and tissue engineering. Still, it is essential to write a comprehensive review article on smart hydrogels that successfully addresses the essential challenging issues in tissue engineering. Hence, the recent development on smart hydrogel for state-of-the-art tissue engineering conferred progress, highlighting significant challenges and future perspectives. This review discusses recent advances in smart hydrogels fabricated from biological macromolecules and their use for advanced tissue engineering. It also provides critical insight, emphasizing future research directions and progress in tissue engineering.
  17. Fulltext Total synthesis, cytotoxic effects of damnacanthal, nordamnacanthal and related anthraquinone analogues
    Akhtar MN, Zareen S, Yeap SK, Ho WY, Lo KM, Hasan A, et al.
    Molecules, 2013 Aug 20;18(8):10042-55.
    PMID: 23966087 DOI: 10.3390/molecules180810042
    Naturally occurring anthraquinones, damnacanthal (1) and nordamnacanthal (2) were synthesized with modified reaction steps and investigated for their cytotoxicity against the MCF-7 and K-562 cancer cell lines, respectively. Intermediate analogues 2-bromomethyl-1,3-dimethoxyanthraquinone (5, IC50 = 5.70 ± 0.21 and 8.50 ± 1.18 mg/mL), 2-hydroxymethyl-1,3-dimethoxyanthraquinone (6, IC50 = 12.10 ± 0.14 and 14.00 ± 2.13), 2-formyl-1,3-dimethoxyantharquinone (7, IC50 = 13.10 ± 1.02 and 14.80 ± 0.74), 1,3-dimethoxy-2-methylanthraquinone (4, IC50 = 9.40 ± 3.51 and 28.40 ± 2.33), and 1,3-dihydroxy-2-methylanthraquinone (3, IC50 = 25.60 ± 0.42 and 28.40 ± 0.79) also exhibited moderate cytotoxicity against MCF-7 and K-562 cancer cell lines, respectively. Other structurally related compounds like 1,3-dihydroxyanthraquinone (13a, IC50 = 19.70 ± 0.35 and 14.50 ± 1.28), 1,3-dimethoxyanthraquinone (13b, IC50 = 6.50 ± 0.66 and 5.90 ± 0.95) were also showed good cytotoxicity. The target compound damnacanthal (1) was found to be the most cytotoxic against the MCF-7 and K-562 cancer cell lines, with IC50 values of 3.80 ± 0.57 and 5.50 ± 1.26, respectively. The structures of all compounds were elucidated with the help of detailed spectroscopic techniques.
  18. Fulltext Are the Radiological and Molecular Features of Pediatric Medulloblastomas Valuable Prognostic Indicators? A 10-Year Retrospective Review in the Middle East
    Alhaj AK, Burhamah T, Mohammad F, Almutawa M, Dashti F, Almurshed M, et al.
    World Neurosurg, 2024 Jul;187:e156-e165.
    PMID: 38636638 DOI: 10.1016/j.wneu.2024.04.057
    BACKGROUND: Medulloblastomas are the most common malignant brain tumors in the pediatric population. Based on the idea that tumors with identical radio-genomic features should behave similarly, the 4 molecular subtypes are now widely accepted as a guide for the management and prognosis. The radiological features of medulloblastomas can predict the molecular subtype; thus, anticipating the subsequent disease progression. However, this has not been evaluated comprehensively. We aim to thoroughly study the association between the molecular subtypes and radiological features of medulloblastomas. Moreover, we aim to investigate the efficacy of this correlation with the use of progression-free survival and 5-year survival rates.

    METHODS: A retrospective analysis was conducted for all histopathological confirmed medulloblastomas in pediatric patients (<16 years old) that were operated on in Kuwait over the past ten years (n = 44). The radiological, histological, and molecular characteristics were justifiably evaluated and analyzed in our sample.

    RESULTS: The overall progression-free survival after one year was noticed among 27 cases (≈44%) and the nonspecific 5-year survival was seen in 31 cases (≈70%) after a 5-year follow-up. Sonic Hedgehog and Wingless had the best outcomes, while group 3 showed the worst outcomes.

    CONCLUSIONS: Our findings did not support the association between most of the typical magnetic resonance imaging characteristics and survival rate. We further established that Sonic Hedgehog and Wingless biological types have a better prognosis. There was no association observed between the radiographic features, specifically the location, and the molecular subtype.

  19. Metal-organic frameworks: synthesis, properties, wound dressing, challenges and scopes in advanced wound dressing
    Khan MUA, Aslam MA, Yasin T, Abdullah MFB, Stojanović GM, Siddiqui HM, et al.
    Biomed Mater, 2024 Jul 16;19(5).
    PMID: 38976990 DOI: 10.1088/1748-605X/ad6070
    Wound healing is a critical but complex biological process of skin tissue repair and regeneration resulting from various systems working together at the cellular and molecular levels. Quick wound healing and the problems associated with traditional wound repair techniques are being overcome with multifunctional materials. Over time, this research area has drawn significant attention. Metal-organic frameworks (MOFs), owning to their peculiar physicochemical characteristics, are now considered a promising class of well-suited porous materials for wound healing in addition to their other biological applications. This detailed literature review provides an overview of the latest developments in MOFs for wound healing applications. We have discussed the synthesis, essential biomedical properties, wound-healing mechanism, MOF-based dressing materials, and their wound-healing applications. The possible major challenges and limitations of MOFs have been discussed, along with conclusions and future perspectives. This overview of the literature review addresses MOFs-based wound healing from several angles and covers the most current developments in the subject. The readers may discover how the MOFs advanced this discipline by producing more inventive, useful, and successful dressings. It influences the development of future generations of biomaterials for the healing and regeneration of skin wounds.
  20. Fulltext Enhancement of mechanical and corrosion resistance properties of electrodeposited Ni-P-TiC composite coatings
    Fayyaz O, Khan A, Shakoor RA, Hasan A, Yusuf MM, Montemor MF, et al.
    Sci Rep, 2021 Mar 05;11(1):5327.
    PMID: 33674680 DOI: 10.1038/s41598-021-84716-6
    In the present study, the effect of concentration of titanium carbide (TiC) particles on the structural, mechanical, and electrochemical properties of Ni-P composite coatings was investigated. Various amounts of TiC particles (0, 0.5, 1.0, 1.5, and 2.0 g L-1) were co-electrodeposited in the Ni-P matrix under optimized conditions and then characterized by employing various techniques. The structural analysis of prepared coatings indicates uniform, compact, and nodular structured coatings without any noticeable defects. Vickers microhardness and nanoindentation results demonstrate the increase in the hardness with an increasing amount of TiC particles attaining its terminal value (593HV100) at the concentration of 1.5 g L-1. Further increase in the concentration of TiC particles results in a decrease in hardness, which can be ascribed to their accumulation in the Ni-P matrix. The electrochemical results indicate the improvement in corrosion protection efficiency of coatings with an increasing amount of TiC particles reaching to ~ 92% at 2.0 g L-1, which can be ascribed to a reduction in the active area of the Ni-P matrix by the presence of inactive ceramic particles. The favorable structural, mechanical, and corrosion protection characteristics of Ni-P-TiC composite coatings suggest their potential applications in many industrial applications.
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