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Visualization of Bacteria-Mediated Gene Delivery Using High-Resolution Electron and Confocal Microscopy

Osahor AN, Ng AWR, Narayanan K

Methods Mol Biol, 2021;2211:29-40.
PMID: 33336268 DOI: 10.1007/978-1-0716-0943-9_3

Visual analysis of the gene delivery process when using invasive bacteria as a vector has been conventionally performed using standard light and fluorescence microscopy. These microscopes can provide basic information on the invasiveness of the bacterial vector including the ability of the vector to successfully adhere to the cell membrane. Standard microscopy techniques however fall short when finer details including membrane attachment as well as internalization into the cytoplasm are desired. High-resolution visual analysis of bacteria-mediated gene delivery can allow accurate measurement of the adherence and internalization capabilities of engineered vectors. Here, we describe the use of scanning electron microscopy (SEM) to directly quantify vectors when they are external to the cell wall, and confocal microscopy to evaluate the vectors when they have internalized into the cytoplasm. By performing the invasion procedure on microscope coverslips, cells can be easily prepared for analysis using electron or confocal microscopes. Imaging the invasion complexes in high resolution can provide important insights into the behavior of bacterial vectors including E. coli, Listeria, and Salmonella when invading their target cells to deliver DNA and other molecules.

Matched MeSH terms: Microscopy, Electron, Scanning
Characterization of pH sensitive sago starch films enriched with anthocyanin-rich torch ginger extract

Xue Mei L, Mohammadi Nafchi A, Ghasemipour F, Mat Easa A, Jafarzadeh S, Al-Hassan AA

Int J Biol Macromol, 2020 Dec 01;164:4603-4612.
PMID: 32941902 DOI: 10.1016/j.ijbiomac.2020.09.082

The development of intelligent packaging based on natural and biodegradable resources is getting more attention by researchers in recent years. The aim of this study was to develop and characterize a pH-sensitive films based on sago starch and incorporated with anthocyanin from torch ginger. The pH-sensitive films were fabricated by casting method with incorporation of different torch ginger extract (TGE) concentration. The surface morphology, physicochemical, barrier, and mechanical properties as well as the pH-sensitivity of films were investigated. The film with the highest concentration of TGE showed the lowest tensile strength (4.26 N/m2), toughness (2.54 MJ/m3), Young's modulus (73.96 MPa) and water vapour permeability (2.6 × 10-4 g·m/day·kPa·m2). However, its elongation at break (85.14%), moisture content (0.27%) and water solubility (37.92%) were the highest compared to other films. pH sensitivity analysis showed that the films containing TGE extract, changes in colour by changing the pH. The colour of films changed from pink to slightly green as the pH increased from pH 4 to 9. Thus, the developed pH-sensitive film with torch ginger extract has potential as intelligent packaging for detection of food freshness or spoilage to ensure their quality and safe consumption.

Matched MeSH terms: Microscopy, Electron, Scanning
Fulltext Lyophilized Amorphous Dispersion of Telmisartan in a Combined Carrier-Alkalizer System: Formulation Development and In Vivo Study

Al-Japairai KAS, Alkhalidi HM, Mahmood S, Almurisi SH, Doolaanea AA, Al-Sindi TA, et al.

ACS Omega, 2020 Dec 22;5(50):32466-32480.
PMID: 33376884 DOI: 10.1021/acsomega.0c04588

Telmisartan suffers from low oral bioavailability due to its poor water solubility. The research work presents a formulation of solid dispersed (SD) telmisartan formulation as a ternary mixture of a drug, a polymeric carrier (poly(vinylpyrrolidone) (PVP) K30), and an alkalizer (Na2CO3). The preparation method, which was lyophilization of an aqueous solution containing the ingredients, was free from any organic solvent. The developed SD formulations resulted in a significant improvement in in vitro dissolution (>90% drug dissolution in 15 min) compared to pure telmisartan. Solid-state characterization by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) studies indicated the conversion of crystalline telmisartan into an amorphous form. Fourier transform infrared (FTIR) spectroscopy revealed the drug-polymer interaction that was responsible for reducing the chances of recrystallization. A short-term stability study showed that selected SD formulations were stable in terms of in vitro dissolution and retained their amorphous structure in ambient and accelerated conditions over 2 months. Selected formulations (drug/PVP K30/Na2CO3 as 1:1:2 or 1:2:2 weight ratio) resulted in >2.48 times relative oral bioavailability compared to marketed formulations. It was considered that the incorporation of an alkalizer and a hydrophilic polymer, and amorphization of telmisartan by lyophilization, could enhance in vitro dissolution and improve oral bioavailability.

Matched MeSH terms: Microscopy, Electron, Scanning
Extracellular Vesicles Derived From Colorectal Cancer Affects CD8 T Cells: An Analysis Based on Body Mass Index

Abu N, Othman N, Ab Razak NS, Bakarurraini NAAR, Nasir SN, Soh JEC, et al.

Front Cell Dev Biol, 2020;8:564648.
PMID: 33324632 DOI: 10.3389/fcell.2020.564648

Colorectal cancer (CRC) is one of the most widely diagnosed cancers worldwide. It has been shown that the body-mass index (BMI) of the patients could influence the tumor microenvironment, treatment response, and overall survival rates. Nevertheless, the mechanism on how BMI affects the tumorigenesis process, particularly the tumor microenvironment is still elusive. Herein, we postulate that extracellular vesicles (EVs) from CRC patients and non-CRC volunteers with different BMI could affect immune cells differently, in CD8 T cells particularly. We isolated the EVs from the archived serum of CRC patients with high and low BMI, as well as healthy controls with similar BMI status. The EVs were further characterized via electron microscopy, western blot and dynamic light scattering. Then, functional analysis was performed on CD8 T cells including apoptosis, cell proliferation, gene expression profiling and cytokine release upon co-incubation with the different EVs. Our results suggest that CRC-derived EVs were able to regulate the CD8 T cells. In some assays, low BMI EVs were functionally different than high BMI EVs. This study highlights the possible difference in the regulatory mechanism of cancer patients-derived EVs, especially on CD8 T cells.

Matched MeSH terms: Microscopy, Electron
Emended description of the genus Actinokineospora Hasegawa 1988 and transfer of Amycolatopsis fastidiosa Henssen et al. 1987 as Actinokineospora fastidiosa comb. nov

Labeda DP, Price NP, Tan GYA, Goodfellow M, Klenk HP

Int J Syst Evol Microbiol, 2010 Jun;60(Pt 6):1444-1449.
PMID: 19671714 DOI: 10.1099/ijs.0.016568-0

The species Amycolatopsis fastidiosa (ex Celmer et al. 1977) Henssen et al. 1987 was proposed, based on morphological and chemotaxonomic observations, for a strain originally described as 'Pseudonocardia fastidiosa' Celmer et al. 1977 in a US patent. In the course of a phylogenetic study of the taxa with validly published names within the suborder Pseudonocardineae based on 16S rRNA gene sequences, it became apparent that this species was misplaced in the genus Amycolatopsis. After careful evaluation of the phylogeny, morphology, chemotaxonomy and physiology of the type strain, it was concluded that this strain represents a species of the genus Actinokineospora that is unable to produce motile spores. The description of the genus Actinokineospora is therefore emended to accommodate species that do not produce motile spores, and it is proposed that Amycolatopsis fastidiosa be transferred to the genus Actinokineospora as Actinokineospora fastidiosa comb. nov. The type strain is NRRL B-16697(T) =ATCC 31181(T) =DSM 43855(T) =JCM 3276(T) =NBRC 14105(T) =VKM Ac-1419(T).

Matched MeSH terms: Microscopy, Electron, Scanning
Dosimetric response of fabricated Ge-doped optical fibres in computed tomography RQT beam quality x-ray beams

Rais NNM, Bradley DA, Hashim A, Isa NM, Osman ND, Ismail I, et al.

J Radiol Prot, 2019 Sep;39(3):N8-N18.
PMID: 31018196 DOI: 10.1088/1361-6498/ab1c16

Novel germanium (Ge)-doped silica glass fibres tailor-made in Malaysia are fast gaining recognition as potential media for thermoluminescence (TL) dosimetry, with active research ongoing into exploitation of their various beneficial characteristics. Investigation is made herein of the capability of these media for use in diagnostic imaging dosimetry, specifically at the radiation dose levels typically obtained in conduct of Computed Tomography (CT). As a first step within such efforts, there is need to investigate the performance of the fibres using tightly defined spectra, use being made of a Philips constant potential industrial x-ray facility, Model MG165, located at the Malaysian Nuclear Agency Secondary Standards Dosimetry Lab (SSDL). Standard radiation beam qualities (termed RQT) have been established for CT, in accord with IEC 61267: 2003 and IAEA Technical Reports Series No. 457: 2007. A calibrated ionisation chamber has also been utilised, forming a component part of the SSDL equipment. The fabricated fibres used in this study are 2.3 mol% flat fibre (FF) of dimensions 643 × 356 μm2 and 2.3 mol% cylindrical fibre (CF) of 481 μm diameter, while the commercial fibre used is 4 mol% with core diameter of 50 μm. The dopant concentrations are nominal preform values. The fibres have been irradiated to doses of 20, 30 and 40 milligray (mGy) for each of the beam qualities RQT 8, RQT 9 and RQT 10. For x-rays generated at constant potential values from 100 to 150 kV, a discernible energy-dependent response is seen, comparisons being made with that of lithium fluoride (LiF) thermoluminescence dosimeters (TLD-100). TL yield versus dose has also been investigated for x-ray doses from 2 to 40 mGy, all exhibiting linearity. Compared to TLD-100, greater sensitivity is observed for the fibres.

Matched MeSH terms: Microscopy, Electron, Scanning
Physicochemical characteristics of microbial content in a modified anaerobic inclining-baffled reactor (MAI-BR) treating recycled paper mill effluent (RPME)

Zwain HM, Chang SM, Dahlan I

Prep Biochem Biotechnol, 2019;49(4):344-351.
PMID: 30712465 DOI: 10.1080/10826068.2019.1566144

Microbial content formed in bioreactors plays a significant role in the anaerobic process. Therefore, the physicochemical characteristics of microbial content in a modified anaerobic inclining-baffled reactor (MAI-BR) treating recycled paper mill effluent (RPME) were investigated using Fourier transform infrared (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric (TG), and derivative thermogravimetric (DTG) analyses, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), Brunauer-Emmett-Teller (BET), and surface area analyzer. FTIR spectra revealed that the microbial content had stronger characteristic peaks corresponding to alcohols, water, lipids carbohydrates, proteins, and mineral compounds. Calcite, muscovite, and lepidolite were the prevalent mineral phases found by XRD analysis. The elemental of these minerals like C, Ca, N, O, and Si was confirmed by XPS results. The microbial content samples from each compartment showed similar thermal behavior. SEM images showed that straight rod-shaped and Methanosaeta-like microorganisms were predominant, whereas C, O, and Ca were noticed by EDS on the surface of granules. The BET surface areas and pores of granules are found to decline throughout the reactor's compartment, where Compartment 1 had the largest values. Thus, the findings of this study establish further understanding of the physicochemical properties of microbial content formed in MAI-BR during the RPME treatment.

Matched MeSH terms: Microscopy, Electron, Scanning
First Report of Hibiscus Chlorotic Ringspot Carmovirus in Tuvalu

Jones P, Devonshire J, Dabek A, Howells C

Plant Dis, 1998 May;82(5):591.
PMID: 30857000 DOI: 10.1094/PDIS.1998.82.5.591C

In September 1997, plants of Hibiscus manihot (locally called nambele) were observed on Vaitupu Island, Tuvalu, exhibiting an angular leaf mosaic and chlorosis that was not always clearly discernible. Electron microscopy of negatively stained sap from affected leaves revealed the presence of numerous isometric virus particles 28 nm in diameter. Poly-acrylamide gel electrophoresis of purified virus gave a single protein band of Mr 38,000 similar to that of the carmoviruses. Immunosorbent electron microscopy tests with antisera kindly provided by N. Spence showed the virus to be hibiscus chlorotic ringspot carmovirus (HCRSV) (1). This virus is also reported from El Salvador, the U.S., Australia, Thailand, Malaysia, Fiji, the Solomon Islands, and Vanuatu. It is not known how the virus reached Tuvalu but we suspect it was via infected cuttings, which were imported for the production of food supplements to combat acute deficiencies of vitamins A and C in the population. The virus is most likely to have been disseminated throughout the islands and atolls of Tuvalu through infected cuttings. Local spread within fields could occur through contaminated hands and cutting implements because of the ease with which the virus is mechanically transmitted. Reference: (1) H. E.Waterworth et al. Phytopathology 66:570, 1976.

Matched MeSH terms: Microscopy, Electron
Fulltext Electrospun Combination of Peppermint Oil and Copper Sulphate with Conducive Physico-Chemical properties for Wound Dressing Applications

Jaganathan SK, Mani MP, Khudzari AZM

Polymers (Basel), 2019 Apr 01;11(4).
PMID: 30960571 DOI: 10.3390/polym11040586

The ultimate goal in tissue engineering is to fabricate a scaffold which could mimic the native tissue structure. In this work, the physicochemical and biocompatibility properties of electrospun composites based on polyurethane (PU) with added pepper mint (PM) oil and copper sulphate (CuSO₄) were investigated. Field Emission Electron microscope (FESEM) study depicted the increase in mean fiber diameter for PU/PM and decrease in fiber diameter for PU/PM/CuSO₄ compared to the pristine PU. Fourier transform infrared spectroscopy (FTIR) analysis revealed the formation of a hydrogen bond for the fabricated composites as identified by an alteration in PU peak intensity. Contact angle analysis presented the hydrophobic nature of pristine PU and PU/PM while the PU/PM/CuSO₄ showed hydrophilic behavior. Atomic force microscopy (AFM) analysis revealed the increase in the surface roughness for the PU/PM while PU/PM/CuSO₄ showed a decrease in surface roughness compared to the pristine PU. Blood compatibility studies showed improved blood clotting time and less toxic behavior for the developed composites than the pristine PU. Finally, the cell viability of the fabricated composite was higher than the pristine PU as indicated in the MTS assay. Hence, the fabricated wound dressing composite based on PU with added PM and CuSO₄ rendered a better physicochemical and biocompatible nature, making it suitable for wound healing applications.

Matched MeSH terms: Microscopy, Electron
Fulltext DNA Adsorption Studies of Poly(4,4'-Cychlohexylidene Bisphenol Oxalate)/Silica Nanocomposites

Al Balawi AN, Yusof NA, Kamaruzaman S, Mohammad F, Wasoh H, Al-Lohedan HA

Materials (Basel), 2019 Apr 11;12(7).
PMID: 30978916 DOI: 10.3390/ma12071178

The present study deals with the synthesis, characterization, and DNA extraction of poly(4,4'-cyclohexylidene bisphenol oxalate)/silica (Si) nanocomposites (NCs). The effects of varying the monomer/Si (3.7%, 7%, and 13%) ratio towards the size and morphology of the resulting NC and its DNA extraction capabilities have also been studied. For the NC synthesis, two different methods were followed, including the direct mixing of poly(4,4'-cyclohexylidene bisphenol oxalate) with fumed Si, and in situ polymerization of the 4,4'-cyclohexylidene bisphenol monomer in the presence of fumed silica (11 nm). The formed NCs were thoroughly investigated by using different techniques such as scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powdered X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) analysis where the results supported that there was the successful formation of poly(4,4'-cyclohexylidene bisphenol oxalate)/Si NC. Within the three different NC samples, the one with 13% Si was found to maintain a very high surface area of 12.237 m²/g, as compared to the other two samples consisting of 7% Si (3.362 m²/g) and 3.7% Si (1.788 m²/g). Further, the solid phase DNA extraction studies indicated that the efficiency is strongly influenced by the amount of polymer (0.2 g > 0.1 g > 0.02 g) and the type of binding buffer. Among the three binding buffers tested, the guanidine hydrochloride/EtOH buffer produced the most satisfactory results in terms of yield (1,348,000 ng) and extraction efficiency (3370 ng/mL) as compared to the other two buffers of NaCl (2 M) and phosphate buffered silane. Based on our results, it can be indicated that the developed poly(4,4'-cyclohexylidene bisphenol oxalate)/Si NC can serve as one of the suitable candidates for the extraction of DNA in high amounts as compared to other traditional solid phase approaches.

Matched MeSH terms: Microscopy, Electron, Scanning
Motorcycle helmet visor-related facial injury and its potential mechanism of injury: Evidence-based case study

Ramli R, Oxley JA

Traffic Inj Prev, 2019;20(3):332-335.
PMID: 30995129 DOI: 10.1080/15389588.2018.1557640

Objectives: We encountered an unusual facial laceration wound in relation to motorcycle helmet visor use during our clinical practice. We aimed to assess the prevalence of this unusual facial injury among motorcyclists who sustained facial injuries in selected hospitals and to determine the possible mechanism involved. Methods: We used our prospective cross-sectional substudy involving injured motorcyclists presenting at major trauma hospitals in Southern Klang Valley, Malaysia, between March 2010 and March 2011. of 391 subjects with facial injuries, 2 male motorcyclists sustained this laceration. The wounds were assessed and we believed that each was associated with the helmet visor. One of the visors was collected and the edge was inspected using scanning electron microscopy (SEM). Results: The prevalence of this unusual injury was 0.51% (95% confidence interval, 0.002-0.012) among motorcyclists who sustained facial injuries. Both cases were involved in a head-on collision with their colliding partners and their helmets were intact throughout the crash. The visor in case 1 was intact, but the visor in case 2 was broken. SEM analysis showed that the visor in case 1 had a potential cutting surface. We postulated that with helmet rotation in the forward and downward position and with some degree of visor bending or with a dislodged visor, the sharp-edged visor could potentially severely lacerate the face. Conclusion: This injury affects facial aesthetics and early referral to the facial surgery team is advocated. Documentation of the mechanism of injury, the patient's helmet and visor is obligatory, so that this information can be delivered to the regional road safety authority for preventive measures.

Matched MeSH terms: Microscopy, Electron, Scanning
Fulltext Single-step purification of the recombinant green fluorescent protein from intact Escherichia coli cells using preparative PAGE

Chew FN, Tan WS, Ling TC, Tey BT

Electrophoresis, 2009 Sep;30(17):3017-3023.
PMID: 19685471 DOI: 10.1002/elps.200900246

Mechanical and non-mechanical breakages of bacterial cells are usually the preliminary steps in intracellular protein purification. In this study, the recombinant green fluorescent protein (GFP) was purified from intact Escherichia coli cells using preparative PAGE. In this purification process, cells disruption step is not needed. The cellular content of E. coli was drifted out electrically from cells and the negatively charged GFP was further electroeluted from polyacrylamide gel column. SEM investigation of the electrophoresed cells revealed substantial structural damage at the cellular level. This integrated purification technique has successfully recovered the intracellular GFP with a yield of 82% and purity of 95%.

Matched MeSH terms: Microscopy, Electron, Scanning
Fulltext The removal of anionic and cationic dyes from an aqueous solution using biomass-based activated carbon

Nizam NUM, Hanafiah MM, Mahmoudi E, Halim AA, Mohammad AW

Sci Rep, 2021 Apr 21;11(1):8623.
PMID: 33883637 DOI: 10.1038/s41598-021-88084-z

In this study, two biomass-based adsorbents were used as new precursors for optimizing synthesis conditions of a cost-effective powdered activated carbon (PAC). The PAC removed dyes from an aqueous solution using carbonization and activation by KOH, NaOH, and H2SO4. The optimum synthesis, activation temperature, time and impregnation ratio, removal rate, and uptake capacity were determined. The optimum PAC was analyzed and characterized using Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), a field emission scanning electron microscope (FESEM), Zeta potential, and Raman spectroscopy. Morphological studies showed single-layered planes with highly porous surfaces, especially PAC activated by NaOH and H2SO4. The results showed that the experimental data were well-fitted with a pseudo-second-order model. Based on Langmuir isotherm, the maximum adsorption capacity for removing methylene blue (MB) was 769.23 mg g-1 and 458.43 mg g-1 for congo red (CR). Based on the isotherm models, more than one mechanism was involved in the adsorption process, monolayer for the anionic dye and multilayer for the cationic dye. Elovich and intraparticle diffusion kinetic models showed that rubber seed shells (RSS) has higher α values with a greater tendency to adsorb dyes compared to rubber seed (RS). A thermodynamic study showed that both dyes' adsorption process was spontaneous and exothermic due to the negative values of the enthalpy (ΔH) and Gibbs free energy (ΔG). The change in removal efficiency of adsorbent for regeneration study was observed in the seventh cycles, with a 3% decline in the CR and 2% decline in MB removal performance. This study showed that the presence of functional groups and active sites on the produced adsorbent (hydroxyl, alkoxy, carboxyl, and π - π) contributed to its considerable affinity for adsorption in dye removal. Therefore, the optimum PAC can serve as efficient and cost-effective adsorbents to remove dyes from industrial wastewater.

Matched MeSH terms: Microscopy, Electron, Scanning
Fulltext Phytogenic Synthesis of Pd-Ag/rGO Nanostructures Using Stevia Leaf Extract for Photocatalytic H2 Production and Antibacterial Studies

Mallikarjuna K, Nasif O, Ali Alharbi S, Chinni SV, Reddy LV, Reddy MRV, et al.

Biomolecules, 2021 01 29;11(2).
PMID: 33572968 DOI: 10.3390/biom11020190

Continuously increasing energy demand and growing concern about energy resources has attracted much research in the field of clean and sustainable energy sources. In this context, zero-emission fuels are required for energy production to reduce the usage of fossil fuel resources. Here, we present the synthesis of Pd-Ag-decorated reduced graphene oxide (rGO) nanostructures using a green chemical approach with stevia extract for hydrogen production and antibacterial studies under light irradiation. Moreover, bimetallic nanostructures are potentially lime lighted due to their synergetic effect in both scientific and technical aspects. Structural characteristics such as crystal structure and morphological features of the synthesized nanostructures were analyzed using X-ray diffraction and transmission electron microscopy. Analysis of elemental composition and oxidation states was carried out by X-ray photoelectron spectroscopy. Optical characteristics of the biosynthesized nanostructures were obtained by UV-Vis absorption spectroscopy, and Fourier transform infrared spectroscopy was used to investigate possible functional groups that act as reducing and capping agents. The antimicrobial activity of the biosynthesized Pd-Ag-decorated rGO nanostructures was excellent, inactivating 96% of Escherichia coli cells during experiments over 150 min under visible light irradiation. Hence, these biosynthesized Pd-Ag-decorated rGO nanostructures can be utilized for alternative nanomaterial-based drug development in the future.

Matched MeSH terms: Microscopy, Electron, Transmission
Fulltext The antibacterial effects of vitamin D3 against mutans streptococci: an in vitro study

Almoudi MMM, Hussein AS, Abu Hassan MI, Al-Talib H, Khan HBSG, Nazli SAB, et al.

Eur Oral Res, 2021 Jan 04;55(1):8-15.
PMID: 33937756 DOI: 10.26650/eor.20210119

Purpose: This study aims to evaluate the antimicrobial effects of the cholecalciferol vitamin D3 against Streptococcus sobrinus (Strep. sobrinus) and Streptococcus mutans (Strep. mutans) bacteria in vitro that is considered the main causative bacteria in dental caries development.
Materials and methods: The antimicrobial effects of vitamin D3 were evaluated against Strep. sobrinus and Strep mutans using the agar disc diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of vitamin D3 were determined using a microdilution method following the guidelines by the Clinical Laboratory Standards Institute (CLSI). Scanning electron microscope (SEM) was used to evaluate the morphological changes of bacterial cells following exposure to vitamin D3.
Results: Strep. sobrinus was more sensitive to vitamin D3 compared to Strep. mutans bacteria. The MIC values of vitamin D3 against Strep. sobrinus and Strep. mutans were 60 μg/ mL and 250 μg/mL respectively whereas the MBC values were 120 μg/mL and 500 μg/mL, respectively. Moreover, significant changes in the bacterial morphology were observed in treated bacterial cells with vitamin D3 as compared to the untreated control bacteria using SEM.
Conclusion: These findings suggested that vitamin D3 has excellent antimicrobial effects against Strep. sobrinus and Strep. mutans and may be considered as a promising compound in the prevention of dental caries in the future. Further research is recommended to elucidate the mechanism of vitamin D3 on these bacteria.

Matched MeSH terms: Microscopy, Electron, Scanning
Fulltext Preparation and characterization of curdlan/polyvinyl alcohol/ thyme essential oil blending film and its application to chilled meat preservation

Zhang Y, Zhou L, Zhang C, Show PL, Du A, Fu J, et al.

Carbohydr Polym, 2020 Nov 01;247:116670.
PMID: 32829798 DOI: 10.1016/j.carbpol.2020.116670

With the growing interest in food safety and in environmental protection, it is more attractive to develop novel biodegradable packaging films. In this regard, one new blending film was prepared with curdlan (CD)/polyvinyl alcohol (PVA)/thyme essential oil. Our results demonstrated that the mechanical properties of the blending film were the best when the ratio of the CD and PVA was 4:1. Further, the barrier properties of the film were optimized by incorporating with thyme essential oil. It was proved that not only water vapor permeability was lower, but also the elongation at break was improved, when 2% (w/w) thyme essential oil used. The potential interactions of the film matrix were analyzed by FTIR, XRD and Cryo-scanning electron microscopy. Importantly, both the antioxidant activity and antibacterial activity were improved. Finally, the blending film was employed for the preservation of chilled meat, while the shelf life was extended up to 10 days.

Matched MeSH terms: Microscopy, Electron, Scanning
Fulltext Gliclazide loaded PLGA-HPMC second generation nanocrystals for oral delivery: design, development and in vitro performance characterization

Krishnamoorthy R., Bibhu Prasad Panda, Shivashekaregowda N. K. H., Low B. S., Bhattamisra S. K.

Malaysian Journal of Medicine and Health Sciences, 2019;15(102):44-44.
MyJurnal

Introduction: Second generation functionalized nanocrystal is the advancement of nanocrystal technology with great potential to accommodate BCS (Biopharmaceutical Classification System) class II drugs to meet their formulation and drug delivery challenges. Gliclazide is a BCS class II drug used in the treatment of type 2 diabetes, shows poor water solubility and low rate of dissolution, leads to poor and variable oral bioavailability. The second generation poly(D,L-lactide-co-glycolide) (PLGA) Hydroxypropyl methylcellulose (HPMC) based functionalized nanocrystals of gliclazide were prepared by a combination method of emulsion diffusion-high pressure homogenization-solvent evaporation. Methods: Gliclazide second generation nanocrystals were fabricated with taguchi orthogonal experimental design in combination of step up and top down nanoformulation strategies using drug-polymer (PLGA) ratio at 1:0.5, 1:0.75, 1:1 with HPMC(0.5, 0.75, 1% w/v) as stabilizer. The formulated gliclazide PLGA-HPMC nanocrystals were investigated on particle size, polydispersity index, zeta potential, solubility study, drug entrapment efficiency, in vitro drug release, and surface morphology and compatibility studies. The gliclazide PLGA nanocrystals formulation was prepared with Drug : PLGA at 1: 1 ratio with concentrations 0.75% w/v HPMC at 5 homogenization cycles with 1000bar produce optimized gliclazide nanocrystals. Results: The optimized MSGNC8 formulation
showed particle size of 239.9 nm, entrapment efficiency 98.62%, and drug release of 43.75%, 82.12% and 98.08% at 3hrs, 24hrs, and 48hrs compared to pure gliclazide % drug release of 28.73%, 67.51% and 78.41% at 3hrs, 24hrs, 48hrs respectively. The solubility study of optimized formulation shows eight folds increased in saturation solubility compared to pure drug. Scanning electron microscopy (SEM) analysis of the gliclazide nanocrystals revealed that
gliclazide retained its crystal morphology in polymeric nanocrystals. Further, fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) studies on gliclazide PLGA-HPMC nanocrystals emphasize drug and excipient compatibility in development of gliclazide nanocrystals. Conclusion: The potential outcomes of research findings emphasize that the developed gliclazide second-generation nanocrystals, which resulted in increase in drug solubility and rate of dissolution with delayed modified release, can be explored in delivery of gliclazide for type 2 diabetes management.

Matched MeSH terms: Microscopy, Electron, Scanning
Adhesion of Lactobacillus isolates to intestinal epithelial cells of chicken

Jin LZ, Ho YW, Ali MA, Abdullah N, Ong KB, Jalaludin S

Lett Appl Microbiol, 1996 Mar;22(3):229-32.
PMID: 8852352

A total of 46 Lactobacillus isolates obtained from chicken intestine were assessed on their ability to adhere to the chicken ileal epithelial cell (IEC) in vitro. Twelve out of the 46 isolates showed moderate to good ability to adhere to the IEC. Temperature (between 4 degrees C and 42 degrees C) did not affect attachment. Incubation (contact) time of 30 min was found to be insufficient for the attachment of bacteria to the IEC, but contact time beyond 1 h did not increase this ability. The pH values (4-7) of the suspending buffer did not have any significant effect on the attachment of bacteria to the IEC, but at pH 8 it was reduced significantly (P < 0.05).

Matched MeSH terms: Microscopy, Electron, Scanning
Fulltext Synthesis of molecularly imprinted polymer for removal of Congo red

Shafqat SR, Bhawani SA, Bakhtiar S, Ibrahim MNM

BMC Chem, 2020 Dec;14(1):27.
PMID: 32266334 DOI: 10.1186/s13065-020-00680-8

Congo red (CR) is an anionic azo dye widely used in many industries including pharmaceutical, textile, food and paint industries. The disposal of huge amount of CR into the various streams of water has posed a great threat to both human and aquatic life. Therefore, it has become an important aspect of industries to remove CR from different water sources. Molecular imprinting technology is a very slective method to remove various target pollutant from environment. In this study a precipitation polymerization was employed for the effective and selective removal of CR from contaminated aqueous media. A series of congo red molecularly imprinted polymers (CR-MIPs) of uniform size and shape was developed by changing the mole ratio of the components. The optimum ratio (0.1:4: 20, template, functional monomer and cross-linking monomer respectively) for CR1-MIP from synthesized polymers was able to rebind about 99.63% of CR at the optimum conditions of adsorption parameters (contact time 210 min, polymer dosage 0.5 g, concentration 20 ppm and pH 7). The synthesized polymers were characterized by various techniques such as Fourier Infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX), and Brumauer-Emmett-Teller (BET). The polymer particles have successfully removed CR from different aqueous media with an efficiency of about ~ 90%.

Matched MeSH terms: Microscopy, Electron, Scanning
Fulltext Morphology, Structural, Thermal, and Tensile Properties of Bamboo Microcrystalline Cellulose/Poly(Lactic Acid)/Poly(Butylene Succinate) Composites

Rasheed M, Jawaid M, Parveez B, Hussain Bhat A, Alamery S

Polymers (Basel), 2021 Feb 01;13(3).
PMID: 33535490 DOI: 10.3390/polym13030465

The present study aims to develop a biodegradable polymer blend that is environmentally friendly and has comparable tensile and thermal properties with synthetic plastics. In this work, microcrystalline cellulose (MCC) extracted from bamboo-chips-reinforced poly (lactic acid) (PLA) and poly (butylene succinate) (PBS) blend composites were fabricated by melt-mixing at 180 °C and then hot pressing at 180 °C. PBS and MCC (0.5, 1, 1.5 wt%) were added to improve the brittle nature of PLA. Field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), thermogravimetric analysis (TGA), differential thermogravimetry (DTG), differential scanning calorimetry (DSC)), and universal testing machine were used to analyze morphology, crystallinity, physiochemical, thermal, and tensile properties, respectively. The thermal stability of the PLA-PBS blends enhanced on addition of MCC up to 1wt % due to their uniform dispersion in the polymer matrix. Tensile properties declined on addition of PBS and increased with MCC above (0.5 wt%) however except elongation at break increased on addition of PBS then decreased insignificantly on addition of MCC. Thus, PBS and MCC addition in PLA matrix decreases the brittleness, making it a potential contender that could be considered to replace plastics that are used for food packaging.

Matched MeSH terms: Microscopy, Electron, Scanning

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