Displaying publications 21 - 40 of 228 in total

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  1. SreeHarsha N, Maheshwari R, Al-Dhubiab BE, Tekade M, Sharma MC, Venugopala KN, et al.
    Int J Nanomedicine, 2019;14:7419-7429.
    PMID: 31686814 DOI: 10.2147/IJN.S211224
    Background: Prostate cancer (PC) has the highest prevalence in men and accounts for a high rate of neoplasia-related death. Doxorubicin (DOX) is one of the most widely used anti-neoplastic drugs for prostate cancer among others. However, it has low specificity and many side effects and affects normal cells. More recently, there have been newly developed drug delivery tools which are graphene or graphene-based, used to increase the specificity of the delivered drug molecules. The graphene derivatives possess both π-π stacking and increased hydrophobicity, factors that increase the likelihood of drug delivery. Despite this, the hydrophilicity of graphene remains problematic, as it induced problems with stability. For this reason, the use of a chitosan coating remains one way to modify the surface features of graphene.

    Method: In this investigation, a hybrid nanoparticle that consisted of a DOX-loaded reduced graphene oxide that is stabilized with chitosan (rGOD-HNP) was developed.

    Result: The newly developed rGOD-HNP demonstrated high biocompatibility and efficiency in entrapping DOX (~65%) and releasing it in a controlled manner (~50% release in 48 h). Furthermore, it was also demonstrated that rGOD-HNP can intracellularly deliver DOX and more specifically in PC-3 prostate cancer cells.

    Conclusion: This delivery tool offers a feasible and viable method to deliver DOX photo-thermally in the treatment of prostate cancer.

    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  2. Gwaram NS, Ali HM, Abdulla MA, Buckle MJ, Sukumaran SD, Chung LY, et al.
    Molecules, 2012 Feb 28;17(3):2408-27.
    PMID: 22374313 DOI: 10.3390/molecules17032408
    Alzheimer's disease (AD) is the most common form of dementia among older people and the pathogenesis of this disease is associated with oxidative stress. Acetylcholinesterase inhibitors with antioxidant activities are considered potential treatments for AD. Some novel ketone derivatives of gallic hydrazide-derived Schiff bases were synthesized and examined for their antioxidant activities and in vitro and in silico acetyl cholinesterase inhibition. The compounds were characterized using spectroscopy and X-ray crystallography. The ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays revealed that all the compounds have strong antioxidant activities. N-(1-(5-bromo-2-hydroxyphenyl)-ethylidene)-3,4,5-trihydroxybenzohydrazide (2) was the most potent inhibitor of human acetyl cholinesterase, giving an inhibition rate of 77% at 100 μM. Molecular docking simulation of the ligand-enzyme complex suggested that the ligand may be positioned in the enzyme's active-site gorge, interacting with residues in the peripheral anionic subsite (PAS) and acyl binding pocket (ABP). The current work warrants further preclinical studies to assess the potential for these novel compounds for the treatment of AD.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  3. Chiu HI, Lim V
    Int J Nanomedicine, 2021;16:2995-3020.
    PMID: 33911862 DOI: 10.2147/IJN.S302238
    PURPOSE: In chemotherapy, oral administration of drug is limited due to lack of drug specificity for localized colon cancer cells. The inability of drugs to differentiate cancer cells from normal cells induces side effects. Colonic targeting with polymeric nanoparticulate drug delivery offers high potential strategies for delivering hydrophobic drugs and fewer side effects to the target site. Disulfide cross-linked polymers have recently acquired high significance due to their potential to degrade in reducing colon conditions while resisting the upper gastrointestinal tract's hostile environment. The goal of this project is, therefore, to develop pH-sensitive and redox-responsive fluorescein-labeled wheat germ agglutinin (fWGA)-mounted disulfide cross-linked alginate nanoparticles (fDTP2) directly targeting docetaxel (DTX) in colon cancer cells.

    METHODS: fDTP2 was prepared by mounting fWGA on DTX-loaded nanoparticles (DTP2) using the two-step carbodiimide method. Morphology of fDTP2 was examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Dynamic light scattering (DLS) study was carried out to determine the mean diameter, polydispersity index (PDI) and zeta potential of fDTP2. Cellular uptake efficiency was examined using fluorescence microplate reader. Biocompatibility and active internalization of fDTP2 were conducted on HT-29.

    RESULTS: fDTP2 was found to exhibit a DTX loading efficiency of 19.3%. SEM and TEM tests revealed spherical nanoparticles. The in vitro DTX release test showed a cumulative release of 54.7%. From the DLS study, fDTP2 reported a 277.7 nm mean diameter with PDI below 0.35 and -1.0 mV zeta potential. HT-29 which was fDTP2-treated demonstrated lower viability than L929 with a half maximal inhibitory concentration (IC50) of 34.7 µg/mL. HT-29 (33.4%) internalized fDTP2 efficiently at 2 h incubation. The study on HT-29 active internalization of nanoparticles through fluorescence and confocal imaging indicated such.

    CONCLUSION: In short, fDTP2 demonstrated promise as a colonic drug delivery DTX transporter.

    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  4. Alshishani A, Salhimi SM, Saad B
    PMID: 29241085 DOI: 10.1016/j.jchromb.2017.12.013
    A new salting-out assisted liquid-liquid extraction (SALLE) sample preparation method for the determination of the polar anti-diabetic biguanide drugs (metformin, buformin and phenformin) in blood plasma, urine and lake water samples were developed. The SALLE was performed by mixing samples (plasma (0.2mL), urine or lake water (1.0mL)) with acetonitrile (0.4mL for plasma, 0.5mL for urine or lake water), sodium hydroxide powder was then added for the phase separation. The effects of type of salting-out reagent, type of extraction solvent, volumes of acetonitrile and sample, amount of sodium hydroxide, vortexing and centrifugation times on the extraction efficiency were investigated. The upper layer, containing the biguanides, was directly injected into a HPLC unit using ZIC-HILIC column (150mm×2.1mm×3.5μm) and was detected at 236nm. The method was validated and calibration curves were linear with r2>0.99 over the range of 20-2000μgL-1for plasma and 5-2000μgL-1for urine and lake water samples. The limits of detection were in the range (3.8-5.6)μgL-1, (0.8-1.5)μgL-1and (0.3-0.8)μgL-1for plasma, urine and lake water, respectively. The accuracies in the three matrices were within 87.3-103%, 87.4-109%, 82.2-109% of the nominal concentration for metformin, buformin and phenformin, respectively. The relative standard deviation for inter- and intra -day precision were in the range of 1.0-17% for all analytes in the three matrices.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  5. Yaacob N, Ahmad Kamarudin NH, Leow ATC, Salleh AB, Raja Abd Rahman RNZ, Mohamad Ali MS
    Molecules, 2017 Aug 12;22(8).
    PMID: 28805665 DOI: 10.3390/molecules22081312
    The alkaline cold-active lipase from Pseudomonas fluorescens AMS8 undergoes major structural changes when reacted with hydrophobic organic solvents. In toluene, the AMS8 lipase catalytic region is exposed by the moving hydrophobic lid 2 (Glu-148 to Gly-167). Solvent-accessible surface area analysis revealed that Leu-208, which is located next to the nucleophilic Ser-207 has a focal function in influencing substrate accessibility and flexibility of the catalytic pocket. Based on molecular dynamic simulations, it was found that Leu-208 strongly facilitates the lid 2 opening via its side-chain. The KM and Kcat/KM of L208A mutant were substrate dependent as it preferred a smaller-chain ester (pNP-caprylate) as compared to medium (pNP-laurate) or long-chain (pNP-palmitate) esters. In esterification of ethyl hexanoate, L208A promotes a higher ester conversion rate at 20 °C but not at 30 °C, as a 27% decline was observed. Interestingly, the wild-type (WT) lipase's conversion rate was found to increase with a higher temperature. WT lipase AMS8 esterification was higher in toluene as compared to L208A. Hence, the results showed that Leu-208 of AMS8 lipase plays an important role in steering a broad range of substrates into its active site region by regulating the flexibility of this region. Leu-208 is therefore predicted to be crucial for its role in interfacial activation and catalysis in toluene.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  6. Mahdi ES, Noor AM, Sakeena MH, Abdullah GZ, Abdulkarim MF, Sattar MA
    Int J Nanomedicine, 2011;6:2499-512.
    PMID: 22072884 DOI: 10.2147/IJN.S22337
    BACKGROUND: Recently there has been a remarkable surge of interest about natural products and their applications in the cosmetic industry. Topical delivery of antioxidants from natural sources is one of the approaches used to reverse signs of skin aging. The aim of this research was to develop a nanoemulsion cream for topical delivery of 30% ethanolic extract derived from local Phyllanthus urinaria (P. urinaria) for skin antiaging.

    METHODS: Palm kernel oil esters (PKOEs)-based nanoemulsions were loaded with P. urinaria extract using a spontaneous method and characterized with respect to particle size, zeta potential, and rheological properties. The release profile of the extract was evaluated using in vitro Franz diffusion cells from an artificial membrane and the antioxidant activity of the extract released was evaluated using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method.

    RESULTS: Formulation F12 consisted of wt/wt, 0.05% P. urinaria extract, 1% cetyl alcohol, 0.5% glyceryl monostearate, 12% PKOEs, and 27% Tween 80/Span 80 (9/1) with a hydrophilic lipophilic balance of 13.9, and a 59.5% phosphate buffer system at pH 7.4. Formulation F36 was comprised of 0.05% P. urinaria extract, 1% cetyl alcohol, 1% glyceryl monostearate, 14% PKOEs, 28% Tween 80/Span 80 (9/1) with a hydrophilic lipophilic balance of 13.9, and 56% phosphate buffer system at pH 7.4 with shear thinning and thixotropy. The droplet size of F12 and F36 was 30.74 nm and 35.71 nm, respectively, and their nanosizes were confirmed by transmission electron microscopy images. Thereafter, 51.30% and 51.02% of the loaded extract was released from F12 and F36 through an artificial cellulose membrane, scavenging 29.89% and 30.05% of DPPH radical activity, respectively.

    CONCLUSION: The P. urinaria extract was successfully incorporated into a PKOEs-based nanoemulsion delivery system. In vitro release of the extract from the formulations showed DPPH radical scavenging activity. These formulations can neutralize reactive oxygen species and counteract oxidative injury induced by ultraviolet radiation and thereby ameliorate skin aging.

    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  7. Shi X, Xu L, Le TB, Zhou G, Zheng C, Tsuru K, et al.
    Mater Sci Eng C Mater Biol Appl, 2016 Feb;59:542-548.
    PMID: 26652406 DOI: 10.1016/j.msec.2015.10.024
    Dental implants made of pure titanium suffer from abrasion and scratch during routine oral hygiene procedures. This results in an irreversible surface damage, facilitates bacteria adhesion and increases risk of peri-implantitis. To overcome these problems, titanium nitride (TiN) coating was introduced to increase surface hardness of pure titanium. However, the osteoconductivity of TiN is considered to be similar or superior to that of titanium and its alloys and therefore surface modification is necessary. In this study, TiN coating prepared through gas nitriding was partially oxidized by hydrothermal (HT) treatment and ozone (O3) treatment in pure water to improve its osteoconductivity. The effects of HT treatment and O3 treatment on surface properties of TiN were investigated and the osteoconductivity after undergoing treatment was assessed in vitro using osteoblast evaluation. The results showed that the critical temperature for HT treatment was 100°C since higher temperatures would impair the hardness of TiN coating. By contrast, O3 treatment was more effective in oxidizing TiN surfaces, improving its wettability while preserving its morphology and hardness. Osteoblast attachment, proliferation, alkaline phosphatase (ALP) expression and mineralization were improved on oxidized specimens, especially on O3 treated specimens, compared with untreated ones. These effects seemed to be consequences of partial oxidation, as well as improved hydrophilicity and surface decontamination. Finally, it was concluded that, partially oxidized TiN is a promising coating to be used for dental implant.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  8. Lau SC, Lim HN, Basri M, Fard Masoumi HR, Ahmad Tajudin A, Huang NM, et al.
    PLoS One, 2014;9(8):e104695.
    PMID: 25127038 DOI: 10.1371/journal.pone.0104695
    In this work, lipase from Candida rugosa was immobilized onto chitosan/graphene oxide beads. This was to provide an enzyme-immobilizing carrier with excellent enzyme immobilization activity for an enzyme group requiring hydrophilicity on the immobilizing carrier. In addition, this work involved a process for the preparation of an enzymatically active product insoluble in a reaction medium consisting of lauric acid and oleyl alcohol as reactants and hexane as a solvent. This product enabled the stability of the enzyme under the working conditions and allowed the enzyme to be readily isolated from the support. In particular, this meant that an enzymatic reaction could be stopped by the simple mechanical separation of the "insoluble" enzyme from the reaction medium. Chitosan was incorporated with graphene oxide because the latter was able to enhance the physical strength of the chitosan beads by its superior mechanical integrity and low thermal conductivity. The X-ray diffraction pattern showed that the graphene oxide was successfully embedded within the structure of the chitosan. Further, the lipase incorporation on the beads was confirmed by a thermo-gravimetric analysis. The lipase immobilization on the beads involved the functionalization with coupling agents, N-hydroxysulfosuccinimide sodium (NHS) and 1-ethyl-(3-dimethylaminopropyl) carbodiimide (EDC), and it possessed a high enzyme activity of 64 U. The overall esterification conversion of the prepared product was 78% at 60 °C, and it attained conversions of 98% and 88% with commercially available lipozyme and novozyme, respectively, under similar experimental conditions.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  9. Lim AK, Goh PP, Azura R, Mariam I
    J Cataract Refract Surg, 2011 Apr;37(4):655-9.
    PMID: 21420589 DOI: 10.1016/j.jcrs.2010.10.050
    PURPOSE: To determine the prevalence of and risk factors for AcriFlex 50CSE hydrophilic acrylic intraocular lens (IOL) opacification approximately 3 years after implantation.
    SETTING: Selayang Hospital, Selangor, Malaysia.
    DESIGN: Cross-sectional study.
    METHODS: Patients who had AcriFlex 50CSE IOL implantation in 2005 and 2006 were identified from operating logbooks and recalled via telephone and letters. Opaque IOLs were explanted and sent for scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS).
    RESULTS: The review showed that 18 patients had died and 67 had declined examination or could not be contacted, leaving 239 eyes for evaluation. The age of the patients ranged from 25 to 85 years. Of the patients, 83 (34.7%) were Malay, 127 (53.1%) Chinese, and 29 (12.1%) East Indian. The male:female ratio was 1:1. Fourteen eyes of 13 patients (5.4%) had IOL opacification; 1 had bilateral opacification. Five eyes had fine deposits, and 9 eyes had dense opaque deposits. Seven opaque IOLs required explantation. There was no correlation between age (P=.645), sex (P=.319), or race (P=.860) and IOL opacification. Pearson chi-square analysis showed a strong association between diabetes mellitus and IOL opacification (P=.019). Nine (69.2%) of the 13 patients with opacification had diabetes. Scanning electron microscopy and EDS showed calcium and phosphate deposits on the optic surface and intralenticularly near the anterior surface of the optic.
    CONCLUSIONS: Results indicate that diabetes mellitus is a risk factor for AcriFlex hydrophilic acrylic IOL opacification. In some cases, opacification affected vision, necessitating explantation. The pathophysiology of this complication is unknown.
    FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  10. Lim SR, Gooi BH, Gam LH
    Cancer Biomark, 2012;12(4):185-98.
    PMID: 23568009 DOI: 10.3233/CBM-130307
    Detection of low abundance proteins always possesses challenges even with the currently available proteomics technologies.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  11. Frimayanti N, Zain SM, Lee VS, Wahab HA, Yusof R, Abd Rahman N
    In Silico Biol. (Gedrukt), 2011;11(1-2):29-37.
    PMID: 22475750 DOI: 10.3233/ISB-2012-0442
    Publication year=2011-2012
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  12. Mohamad SB, Ong AL, Khairuddin RF, Ripen AM
    In Silico Biol. (Gedrukt), 2010;10(3):145-53.
    PMID: 22430288 DOI: 10.3233/ISB-2010-0423
    Laccases are industrially attractive enzymes and their applications have expanded to the field of bioremediation. The challenge of today's biotechnology in enzymatic studies is to design enzymes that not only have a higher activity but are also more stable and could fit well with the condition requirements. Laccases are known to oxidize non-natural substrates like polycyclic aromatic hydrocarbons (PAHs). We suppose by increasing the hydrophobicity of laccase, it would increase the chance of the enzyme to meet the hydrophobic substrates in a contamination site, therefore increasing the bioremediation efficacy of PAHs from environment. In this attempt, the applications of evolutionary trace (ET), molecular surface accessibility and hydrophobicity analysis on laccase sequences and laccase's crystal structure (1KYA) are described for optimal design of an enzyme with higher hydrophobicity. Our analysis revealed that Q23A, Q45I, N141A, Q237V, N262L, N301V, N331A, Q360L and Q482A could be promising exchanges to be tested in mutagenesis experiments.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  13. Liang S, Singh M, Gam LH
    Cancer Biomark, 2010;8(6):319-30.
    PMID: 22072120 DOI: 10.3233/CBM-2011-0221
    Breast cancer is a leading cause of worldwide mortality in females. In Malaysia, breast cancer is the most commonly diagnosed cancer in women. Of these, the Chinese had the most number of breast cancer cases, followed by the Indian and the Malay. The most common type of breast cancer is infiltrating ductal carcinoma (IDC). A proteomic approach was used to identify protein profile changes in cancerous tissues compared with the normal tissues, the tissues were collected from patients of three different ethnicities, i.e. Chinese, Malay and Indian. Ten differentially expressed hydrophobic proteins were identified. We had evaluated the potential of these proteins as biomarker for infiltrating ducal carcinoma (IDC) and the ethnic-specific expression of these proteins was also determined. The data showed that peroxiredoxin-2, heat shock protein 60, protein disulfide isomerase and calreticulin may serve as ethnic-related potential markers for either one or combination of Chinese, Malay and Indian cohorts as their expression levels were significantly high in the cancerous tissues compared to the normal tissues in the ethnic group tested.
    Publication year=2010-2011
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  14. Rahim ZH, Khan HB
    J Oral Sci, 2006 Sep;48(3):117-23.
    PMID: 17023743
    A study was conducted to compare the efficiency of crude aqueous (CA) and solvent extracts (CM) of clove on the caries-inducing properties of Streptococcus mutans. The cariogenic properties investigated included the cell adhesion, cell-surface hydrophobicity and glucan synthesis activities of S. mutans. There was a significant difference between the effect of the CA and CM extracts on the adhesion of S. mutans (P < 0.05) within a concentration range of 5-15 mg/ml, the CM extract demonstrating a slightly higher inhibitory effect. However, the effect of the CM extract on the cell-surface hydrophobicity of S. mutans was weaker than that of the CA extract. The two extracts were found to reduce the synthesis of water-insoluble glucan (WIG) by almost 50% at a concentration as low as 0.5 mg/ml and the CM extract exhibited a significantly higher inhibitory effect than the CA extract (P < 0.05). The present findings indicate that both the CA and CM extracts exert inhibitory effects on the cariogenic properties of S. mutans and that the CA extract is as equally effective as the CM extract.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  15. Kiran SA, Arthanareeswaran G, Thuyavan YL, Ismail AF
    Ecotoxicol Environ Saf, 2015 Nov;121:186-92.
    PMID: 25869419 DOI: 10.1016/j.ecoenv.2015.04.001
    In this study, modified polyethersulfone (PES) and cellulose acetate (CA) membranes were used in the treatment of car wash effluent using ultrafiltration. Hydrophilic sulfonated poly ether ether ketone (SPEEK) and bentonite as nanoclay were used as additives for the PES and CA membrane modification. Performances of modified membranes were compared with commercial PES membrane with 10kDa molecular weight cut off (MWCO). The influencing parameters like stirrer speed (250-750rpm) and transmembrane pressure (100-600kPa) (TMP) were varied and their effects were studied as a function of flux. In the treatment of car wash effluent, a higher permeate flux of 52.3L/m(2)h was obtained for modified CA membrane at TMP of 400kPa and stirrer speed of 750rpm. In comparison with modified PES membrane and commercial PES membrane, modified CA membranes showed better performance in terms of flux and flux recovery ratio. The highest COD removal (60%) was obtained for modified CA membrane and a lowest COD removal (47%) was observed for commercial PES membrane. The modified membranes were better at removing COD, turbidity and maintained more stable flux than commercial PES membrane, suggesting they will provide better economic performance in car wash effluent reclamation.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  16. Salleh AB, Basri M, Taib M, Jasmani H, Rahman RN, Rahman MB, et al.
    Appl Biochem Biotechnol, 2002 10 25;102-103(1-6):349-57.
    PMID: 12396136
    Recent studies on biocatalysis in water-organic solvent biphasic systems have shown that many enzymes retain their catalytic activities in the presence of high concentrations of organic solvents. However, not all enzymes are organic solvent tolerant, and most have limited and selective tolerance to particular organic solvents. Protein modification or protein tailoring is an approach to alter the characteristics of enzymes, including solubility in organic solvents. Particular amino acids may play pivotal roles in the catalytic ability of the protein. Attaching soluble modifiers to the protein molecule may alter its conformation and the overall polarity of the molecule. Enzymes, in particular lipases, have been chemically modified by attachment of aldehydes, polyethylene glycols, and imidoesters. These modifications alter the hydrophobicity and conformation of the enzymes, resulting in changes in the microenvironment of the enzymes. By these modifications, newly acquired properties such as enhancement of activity and stability and changes in specificity and solubility in organic solvents are obtained. Modified lipases were found to be more active and stable in organic solvents. The optimum water activity (a(w)) for reaction was also shifted by using modified enzymes. Changes in enantioselective behavior were also observed.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  17. Razak FA, Rahim ZH
    J Oral Sci, 2003 Dec;45(4):201-6.
    PMID: 14763515
    The aqueous extracts of Piper betle and Psidium guajava were prepared and tested for their anti-adherence effect on the adhesion of early plaque settlers (Strep. mitis, Strep. sanguinis and Actinomyces sp.). The saliva-coated glass surfaces were used to simulate the pellicle-coated enamel surface in the oral cavity. Our results showed that the anti-adherence activities of Piper betle and Psidium guajava extracts towards the bacteria were different between the bacterial species. Psidium guajava was shown to have a slightly greater anti-adherence effect on Strep. sanguinis by 5.5% and Actinomyces sp. by 10% and a significantly higher effect on Strep. mitis (70%) compared to Piper betle. The three bacterial species are known to be highly hydrophobic, and that hydrophobic bonding seemed to be an important factor in their adherence activities. It is therefore suggested that the plant extracts, in expressing their anti-adherence activities, could have altered the hydrophobic nature of the bonding between the bacteria and the saliva-coated glass surfaces.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  18. Hamid TH, Rahman RN, Salleh AB, Basri M
    Protein J, 2010 May;29(4):290-7.
    PMID: 20509044 DOI: 10.1007/s10930-010-9251-7
    The use of lipase in hydrophilic solvent is usually hampered by inactivation. The solvent stability of a recombinant solvent stable lipase isolated from thermostable Bacillus sp. strain 42 (Lip 42), in DMSO and methanol were studied at different solvent-water compositions. The enzymatic activities were retained in up to 45% v/v solvent compositions. The near-UV CD spectra indicated that tertiary structures were perturbed at 60% v/v and above. Far-UV CD in methanol indicated the secondary structure in Lip 42 was retained throughout all solvent compositions. Fluorescence studies indicated formations of molten globules in solvent compositions of 60% v/v and above. The enzyme was able to retain its secondary structures in the presence of methanol; however, there was a general reduction in beta-sheet and an increase in alpha-helix contents. The H-bonding arrangements triggered in methanol and DMSO, respectively, caused different forms of tertiary structure perturbations on Lip 42, despite both showing partial denaturation with molten globule formations.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  19. Kumar M, RaoT S, Isloor AM, Ibrahim GPS, Inamuddin, Ismail N, et al.
    Int J Biol Macromol, 2019 May 15;129:715-727.
    PMID: 30738161 DOI: 10.1016/j.ijbiomac.2019.02.017
    Cellulose acetate (CA) and cellulose acetate phthalate (CAP) were used as additives (1 wt%, 3 wt%, and 5 wt%) to prepare polyphenylsulfone (PPSU) hollow fiber membranes. Prepared hollow fiber membranes were characterized by surface morphology using scanning electron microscopy (SEM), surface roughness by atomic force microscopy (AFM), the surface charge of the membrane was analyzed by zeta potential measurement, hydrophilicity by contact angle measurement and the functional groups by fourier transform infrared spectroscopy (FTIR). Fouling resistant nature of the prepared hollow fiber membranes was evaluated by bovine serum albumin (BSA) and molecular weight cutoff was investigated using polyethylene glycol (PEG). By total organic carbon (TOC), the percentage rejection of PEG was found to be 14,489 Da. It was found that the hollow fiber membrane prepared by the addition of 5 wt% of CAP in PPSU confirmed increased arsenic removal from water as compared to hollow fiber membrane prepared by 5 wt% of CA in PPSU. The removal percentages of arsenic with CA-5 and CAP-5 hollow fiber membrane was 34% and 41% with arsenic removal permeability was 44.42 L/m2h bar and 40.11 L/m2h bar respectively. The increased pure water permeability for CA-5 and CAP-5 hollow fiber membrane was 61.47 L/m2h bar and 69.60 L/m2 h bar, respectively.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
  20. Kamath SM, Sridhar K, Jaison D, Gopinath V, Ibrahim BKM, Gupta N, et al.
    Sci Rep, 2020 10 23;10(1):18179.
    PMID: 33097770 DOI: 10.1038/s41598-020-74885-1
    Modulation of initial burst and long term release from electrospun fibrous mats can be achieved by sandwiching the drug loaded mats between hydrophobic layers of fibrous polycaprolactone (PCL). Ibuprofen (IBU) loaded PCL fibrous mats (12% PCL-IBU) were sandwiched between fibrous polycaprolactone layers during the process of electrospinning, by varying the polymer concentrations (10% (w/v), 12% (w/v)) and volume of coat (1 ml, 2 ml) in flanking layers. Consequently, 12% PCL-IBU (without sandwich layer) showed burst release of 66.43% on day 1 and cumulative release (%) of 86.08% at the end of 62 days. Whereas, sandwich groups, especially 12% PCLSW-1 & 2 (sandwich layers-1 ml and 2 ml of 12% PCL) showed controlled initial burst and cumulative (%) release compared to 12% PCL-IBU. Moreover, crystallinity (%) and hydrophobicity of the sandwich models imparted control on ibuprofen release from fibrous mats. Further, assay for cytotoxicity and scanning electron microscopic images of cell seeded mats after 5 days showed the mats were not cytotoxic. Nuclear Magnetic Resonance spectroscopic analysis revealed weak interaction between ibuprofen and PCL in nanofibers which favors the release of ibuprofen. These data imply that concentration and volume of coat in flanking layer imparts tighter control on initial burst and long term release of ibuprofen.
    Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
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