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Displaying publications 121 - 140 of 229 in total

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Opacification of AcriFlex 50CSE hydrophilic acrylic intraocular lenses

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
Manipulation of nanofiber-based β-galactosidase nanoenvironment for enhancement of galacto-oligosaccharide production

Misson M, Dai S, Jin B, Chen BH, Zhang H

J Biotechnol, 2016 Mar 20;222:56-64.
PMID: 26876609 DOI: 10.1016/j.jbiotec.2016.02.014

The nanoenvironment of nanobiocatalysts, such as local hydrophobicity, pH and charge density, plays a significant role in optimizing the enzymatic selectivity and specificity. In this study, Kluyveromyces lactis β-galactosidase (Gal) was assembled onto polystyrene nanofibers (PSNFs) to form PSNF-Gal nanobiocatalysts. We proposed that local hydrophobicity on the nanofiber surface could expel water molecules so that the transgalactosylation would be preferable over hydrolysis during the bioconversion of lactose, thus improve the galacto-oligosaccharides (GOS) yield. PSNFs were fabricated by electro-spinning and the operational parameters were optimized to obtain the nanofibers with uniform size and ordered alignment. The resulting nanofibers were functionalized for enzyme immobilization through a chemical oxidation method. The functionalized PSNF improved the enzyme adsorption capacity up to 3100mg/g nanofiber as well as enhanced the enzyme stability with 80% of its original activity. Importantly, the functionalized PSNF-Gal significantly improved the GOS yield and the production rate was up to 110g/l/h in comparison with 37g/l/h by free β-galactosidase. Our research findings demonstrate that the localized nanoenvironment of the PSNF-Gal nanobiocatalysts favour transgalactosylation over hydrolysis in lactose bioconversion.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Enhanced secretion of cyclodextrin glucanotransferase (CGTase) by Lactococcus lactis using heterologous signal peptides and optimization of cultivation conditions

Mahmud H, Ismail A, Abdul Rahim R, Low KO, Md Illias R

J Biotechnol, 2019 Apr 20;296:22-31.
PMID: 30878516 DOI: 10.1016/j.jbiotec.2019.02.013

In previous studies of Lactococcus lactis, the levels of proteins secreted using heterologous signal peptides were observed to be lower than those obtained using the signal peptide from Usp45, the major secreted lactococcal protein. In this study, G1 (the native signal peptide of CGTase) and the signal peptide M5 (mutant of the G1 signal peptide) were introduced into L. lactis to investigate the effect of signal peptides on lactococcal protein secretion to improve secretion efficiency. The effectiveness of these signal peptides were compared to the Usp45 signal peptide. The highest secretion levels were obtained using the G1 signal peptide. Sequence analysis of signal peptide amino acids revealed that a basic N-terminal signal peptide is not absolutely required for efficient protein export in L. lactis. Moreover, the introduction of a helix-breaking residue in the H-region of the M5 signal peptide caused a reduction in the signal peptide hydrophobicity and decreased protein secretion. In addition, the optimization of cultivation conditions for recombinant G1-CGTase production via response surface methodology (RSM) showed that CGTase activity increased approximately 2.92-fold from 5.01 to 16.89 U/ml compared to the unoptimized conditions.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Characterization of alcohol/salt aqueous two-phase system for optimal separation of gallic acids

Ng HS, Kee PE, Yim HS, Tan JS, Chow YH, Lan JC

J Biosci Bioeng, 2021 May;131(5):537-542.
PMID: 33674222 DOI: 10.1016/j.jbiosc.2021.01.004

Gallic acid (GA) is a hydrophilic polyphenol which is noteworthy for strong antioxidant capacity. The drawbacks of conventional extraction approaches such as time-consuming and high processing cost are often viewed as a hurdle to extract GA from plant sources in industrial scale. Aqueous two-phase system (ATPS) is a separation approach which can be employed as an alternative to the conventional approaches. The partition behaviour of GA in an alcohol/salt ATPS was investigated in this study to aid the development of industrial scale ATPS to extract GA from natural sources. The separation of GA was characterized by determining the types of alcohol and salt, phase composition, sample load, pH of the system and addition of adjuvants applied in the alcohol/salt ATPS construction. The hydrophilic GA was targeted to the salt-rich phase of the alcohol/salt ATPS with a partition coefficient (KGA) of 25.00 ± 0.00. The optimum condition of ATPS for the maximum partition of GA was achieved in ATPS comprised of 24% (w/w) 1-propanol and 22% (w/w) phosphate salt at pH 8 with 5% (w/w) of 1 mg/mL sample loading and 2% (w/w) NaCl addition. The findings suggest that ATPS can be applied for separation of GA from various natural sources.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Exploring the combination characteristics of lumefantrine, an antimalarial drug and human serum albumin through spectroscopic and molecular docking studies

Musa KA, Ridzwan NFW, Mohamad SB, Tayyab S

J Biomol Struct Dyn, 2021 Feb;39(2):691-702.
PMID: 31913089 DOI: 10.1080/07391102.2020.1713215

Binding of lumefantrine (LUM), an antimalarial drug to human serum albumin (HSA), the main carrier protein in human blood circulation was investigated using fluorescence quenching titration, UV-vis absorption and circular dichroism (CD) spectroscopy as well as molecular docking. LUM-induced quenching of the protein (HSA) fluorescence was characterized as static quenching, as revealed by the decrease in the value of the Stern-Volmer quenching constant, K
sv
with increasing temperature, thus suggesting LUM-HSA complex formation. This was also confirmed from the UV-vis absorption spectral results. Values of the association constant, Ka for LUM-HSA interaction were found to be within the range, 7.27-5.01 × 104 M-1 at three different temperatures, i.e. 288 K, 298 K and 308 K, which indicated moderate binding affinity between LUM and HSA. The LUM-HSA complex was stabilized by hydrophobic interactions, H-bonds, as well as van der Waals forces, as predicted from the thermodynamic data (ΔS = +50.34 J mol-1 K-1 and ΔH = -12.3 kJ mol-1) of the binding reaction. Far-UV and near-UV CD spectral results demonstrated smaller changes in both secondary and tertiary structures of HSA upon LUM binding, while three-dimensional fluorescence spectra suggested alterations in the microenvironment around protein fluorophores (Trp and Tyr). LUM binding to HSA offered stability to the protein against thermal stress. Competitive drug displacement results designated Sudlow's Site I, located in subdomain IIA of HSA as the preferred binding site of LUM on HSA, which was well supported by molecular docking analysis.Communicated by Ramaswamy H. Sarma.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Biomolecular interaction of a platelet aggregation inhibitor, 3,4-methylenedioxy-β-nitrostyrene with human serum albumin: multi-spectral and computational characterization

Kabir MZ, Roslan AA, Ridzwan NFW, Mohamad SB, Tayyab S

J Biomol Struct Dyn, 2020 Jun;38(9):2693-2703.
PMID: 31271347 DOI: 10.1080/07391102.2019.1640133

Molecular interaction of the 3,4-methylenedioxy-β-nitrostyrene (MNS), an inhibitor of platelet aggregation with the main transport protein, albumin from human serum (HSA) was explored using absorption, fluorescence and circular dichroism (CD) spectroscopy in combination with in silico analyses. The MNS-HSA complexation was corroborated from the fluorescence and absorption spectral results. Implication of static quenching mechanism for MNS-HSA system was predicted from the Stern-Volmer constant, KSV-temperature relationship as well as the bimolecular quenching rate constant, kq values. Stabilization of the complex was affirmed by the value of the binding constant (Ka = 0.56-1.48 × 104 M-1). Thermodynamic data revealed that the MNS-HSA association was spontaneously driven mainly through hydrophobic interactions along with van der Waal's interaction and H-bonds. These results were well supported by in silico interpretations. Far-UV and near-UV CD spectral results manifested small variations in the protein's secondary and tertiary structures, respectively, while three-dimensional fluorescence spectra displayed microenvironmental fluctuations around protein's fluorophores, upon MNS binding. Significant improvement in the protein's thermostability was evident from the temperature-stability results of MNS-bound HSA. Binding locus of MNS, as identified by competitive drug displacement findings as well as in silico analysis, was found to be located in subdomain IIA (Sudlow's site I) of the protein.Communicated by Ramaswamy H. Sarma.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Synthesis and functionalization of chitosan built hydrogel with induced hydrophilicity for extended release of sparingly soluble drugs

Ullah F, Javed F, Othman MBH, Khan A, Gul R, Ahmad Z, et al.

J Biomater Sci Polym Ed, 2018 03;29(4):376-396.
PMID: 29285989 DOI: 10.1080/09205063.2017.1421347

Addressing the functional biomaterials as next-generation therapeutics, chitosan and alginic acid were copolymerized in the form of chemically crosslinked interpenetrating networks (IPNs). The native hydrogel was functionalized via carbodiimide (EDC), catalyzed coupling of soft ligand (1,2-Ethylenediamine) and hard ligand (4-aminophenol) to replace -OH groups in alginic acid units for extended hydrogel- interfaces with the aqueous and sparingly soluble drug solutions. The chemical structure, Lower solution critical temperature (LCST ≈ 37.88 °C), particle size (Zh,app ≈ 150-200 nm), grain size (160-360 nm), surface roughness (85-250 nm), conductivity (37-74 mv) and zeta potential (16-32 mv) of native and functionalized hydrogel were investigated by using FT-IR, solid state-13C-NMR, TGA, DSC, FESEM, AFM and dynamic light scattering (DLS) measurements. The effective swelling, drug loading (47-78%) and drug release (53-86%) profiles were adjusted based on selective functionalization of hydrophobic IPNs due to electrostatic complexation and extended interactions of hydrophilic ligands with the aqueous and drug solutions. Drug release from the hydrogel matrices with diffusion coefficient n ≈ 0.7 was established by Non- Fickian diffusion mechanism. In vitro degradation trials of the hydrogel with a 20% loss of wet mass in simulated gastric fluid (SGF) and 38% loss of wet mass in simulated intestinal fluid (SIF), were investigated for 400 h through bulk erosion. Consequently, a slower rate of drug loading and release was observed for native hydrogel, due to stronger H-bonding, interlocking and entanglement within the IPNs, which was finely tuned and extended by the induced hydrophilic and functional ligands. In the light of induced hydrophilicity, such functional hydrogel could be highly attractive for extended release of sparingly soluble drugs.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Influence of citric acid on the physical and biomineralization ability of freeze/thaw poly(vinyl alcohol) hydrogel

Wahid MNA, Abd Razak SI, Abdul Kadir MR, Hassan R, Nayan NHM, Mat Amin KA

J Biomater Appl, 2018 07;33(1):94-102.
PMID: 29716417 DOI: 10.1177/0885328218771195

This work reports the modification of freeze/thaw poly(vinyl alcohol) hydrogel using citric acid as the bioactive molecule for hydroxyapatite formation in simulated body fluid. Inclusion of 1.3 mM citric acid into the poly(vinyl alcohol) hydrogel showed that the mechanical strength, crystalline phase, functional groups and swelling ability were still intact. Adding citric acid at higher concentrations (1.8 and 2.3 mM), however, resulted in physically poor hydrogels. Presence of 1.3 mM of citric acid showed the growth of porous hydroxyapatite crystals on the poly(vinyl alcohol) surface just after one day of immersion in simulated body fluid. Meanwhile, a fully covered apatite layer on the poly(vinyl alcohol) surface plus the evidence of apatite forming within the hydrogel were observed after soaking for seven days. Gel strength of the soaked poly(vinyl alcohol)/citric acid-1.3 mM hydrogel revealed that the load resistance was enhanced compared to that of the neat poly(vinyl alcohol) hydrogel. This facile method of inducing rapid growth of hydroxyapatite on the hydrogel surface as well as within the hydrogel network can be useful for guided bone regenerative materials.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Multispectroscopic and molecular modeling approach to investigate the interaction of flavokawain B with human serum albumin

Feroz SR, Mohamad SB, Bujang N, Malek SN, Tayyab S

J Agric Food Chem, 2012 Jun 13;60(23):5899-908.
PMID: 22624666 DOI: 10.1021/jf301139h

Interaction of flavokawain B (FB), a multitherapeutic flavonoid from Alpinia mutica with the major transport protein, human serum albumin (HSA), was investigated using different spectroscopic probes, i.e., intrinsic, synchronous, and three-dimensional (3-D) fluorescence, circular dichroism (CD), and molecular modeling studies. Values of binding parameters for FB-HSA interaction in terms of binding constant and stoichiometry of binding were determined from the fluorescence quench titration and were found to be 6.88 × 10(4) M(-1) and 1.0 mol of FB bound per mole of protein, respectively, at 25 °C. Thermodynamic analysis of the binding data obtained at different temperatures showed that the binding process was primarily mediated by hydrophobic interactions and hydrogen bonding, as the values of the enthalpy change (ΔH) and the entropy change (ΔS) were found to be -6.87 kJ mol(-1) and 69.50 J mol(-1) K(-1), respectively. FB binding to HSA led to both secondary and tertiary structural alterations in the protein as revealed by intrinsic, synchronous, and 3-D fluorescence results. Increased thermal stability of HSA in the presence of FB was also evident from the far-UV CD spectral results. The distance between the bound ligand and Trp-214 of HSA was determined as 3.03 nm based on the Förster resonance energy transfer mechanism. Displacement experiments using bilirubin and warfarin coupled with molecular modeling studies assigned the binding site of FB on HSA at domain IIA, i.e., Sudlow's site I.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Fulltext Synthesis and characterization of cis-5-norbornene-2, 3-dicarboxylic anhydride-chitosan

Ku Marsilla Ku Ishak, Zulkifli Ahmad, Hazizan Md Akil

Journal of Nuclear and Related Technologies, 2009;2009(1):111-120.
MyJurnal

Chitosan was chemically modified with bulky structure, cis-5-norbornene-2, 3-dicarboxylic anhydride and the characteristic of this modified chitosan was studied. The resulting material was analyzed by FTIR, TGA, DSC, XRD and SEM to study the effect of N-acylation to the polysaccharide structure. FTIR results show that the anhydride monomer was successfully bound to amine group of chitosan. Thermal analysis of the modified structure provides the chitosan fibers with thermal stability while XRD and SEM show the lost of crystallinity of modified chitosan. XRD of modified chitosan shows broader peak pattern and a considerable increase in a dimension while SEM of chitosan presented the single particle morphology while norbornene-chitosan shows aggromolarate behaviour due to the hydrophobic nature of norbornene pendant group which induced aggromolaration of the particles in modified structure.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Fulltext Tensile properties of alkaline treated coconut meat husk reinforced polyester composites

Muhammad Faiz Ghazali, Mohamad Juraidi Jamal, Syed Azuan Syed Ahmad

Journal of Engineering and Science Research, 2017;1(1):4-7.
MyJurnal

Synthetic fibers such as glass fiber and carbon fiber are traditionally used as reinforcement in engineering composites. The increasing of environmental concerns has led to the use of natural fibers as renewable alternatives reinforcement. Among them, coconut meat husk fiber which abundant availability can be used as reinforcement fiber. However, the coconut meat husk fiber, same as other natural fibers, has the issues of fiber/matrix bonding and moisture absorption. Chemical treatments are needed to modify the surface of fiber, aiming at improving the adhesion with polymer matrix and reducing the hydrophilicity of the fiber. Alkalization was used in this study to treat the coconut meat husk fiber. The effects of chemical treatments for 1hr and 24 hr treatment time on the coconut meat husk fibers reinforced composites were investigated. A result showed that the 24 hr alkali treatment gave the highest tensile stenght compared to the 1hr treatment and RO water.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Fulltext Combining docking and molecular dynamic of protease from Bacillus lehensis G1

Noorul Aini Sulaiman, Nur Zazarina Ramly, Shuhaila Mat-Sharani, Nor Muhammad Mahadi

Journal of Engineering and Science Research, 2018;2(1):1-5.
MyJurnal

Protease is an enzyme that catalysed the hydrolysis of protein into peptide. Application of protease in industry has been linked with cost effective substrates and complex of enzyme-substrate stability. Molecular docking approach has identified casein as a preference substrates. However, lack of data on casein mode of binding to protease and enzyme stability represents a limitation for its production and structural optimization. In this study, we have used a molecular dynamic (MD) to examine the stability of complex enzyme-substrate of protease from Bacillus lehensis G1. The 3D structure of protease (BleG1_1979) was docked with substrate casein using AutoDock Vina. Structural analysis of the substrate-binding cleft revealed a binding site of casein was predominantly at the hydrophobic region of BleG1_1979. The MD of complex BleG1_1979-casein was tested with two temperatures; 298 K and 310 K using GROMACS v5.1.4. MD simulation showed a stable behaviour of BleG1_1979 over the 20 ns simulation period. The molecular docking and MD simulation suggested that the production of protease from B. lehensis G1 by utilization of casein and the stability of complex protease-casein could be a potential application to generate a cost effective enzyme to be develop for industrial use.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Fulltext Optimization of monoclonal antibodies purification expressed in H-192 cells using preparative native-polyacrylamide gel electrophoresis

Krishnan, Santhana, Mimi Sakinah Abdul Munaim, Zularisam Abdul Wahid, Chua, Yeo Gek Kee, Chew, Few Nee

Journal of Biochemistry, Microbiology and Biotechnology, 2015;3(1):21-25.
MyJurnal

Monoclonal antibodies (mAbs) are unique and specific drug molecules targeting the treatment of various diseases such as arthritis, immune disorders, infectious diseases, and cancer etc. Different methods such as antibody coupled affinity chromatography, hydrophobic interaction chromatography, etc., can be applied to purify mAbs from various sources. This article provides a simple, cost effective, preparative native-polyacrylamide gel electrophoresis (n-PAGE)technique to purify mAbs expressed in H-192 cells (Hybridoma murine cell lines) against an antigen i.e. 17-alpha-hydroxyprogesterone (17-OHP), which further can have diagnostic application to detect Congenital Adrenal Hyperplasia (CAH). Furthermore, different parameters such as concentration and volume of the feedstock (medium containing antibodies), pore size of gel, height of resolving gel etc. were optimized to obtain the maximum purity and yield of mAbs.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Fulltext Reinventing nano drug delivery systems for hydrophilic active ingredients in Ayurvedic lipid based formulations containing poly herbal decoction

Duraipandi S, Selvakumar V

J Ayurveda Integr Med, 2019 01 08;11(3):224-227.
PMID: 30635246 DOI: 10.1016/j.jaim.2018.01.008

BACKGROUND: Anu Tailam, an Ayurvedic medicated oil where 'anu' meant for atom and 'tailam' meant for oil and virtually meant for 'oil of subtle or atomic size particles'. Since the major active ingredients in this formulation are incorporated from the polyherbal decoction, it is expected to contain predominantly water soluble ingredients.
OBJECTIVES: It is hypothesized that these polar active botanical ingredients are present in the formulation should be either suspended in the form of submicron particles or entrapped in the submicron vesicular structures since the formulation did not show any precipitation or phase separation instead showed a monophasic oily liquid with very little moisture.
MATERIALS AND METHODS: In the present investigation, the micro architecture of the anu tailam is studied via column chromatography and high performance thin layer chromatography to prove the contents are polar hydrophilic compounds followed by optical microscopy, photon correlation Spectroscopy (PCS) and environmental scanning electron microscope (ESEM) to study the particle/vesicle size of the formulation.
RESULTS: In this study, it was proved that the formulation contained only polar ingredients and can be extracted in polar solvents like methanol and ethanol. It was also found that the formulation taken for study contained nano particles of the active botanical ingredients embedded in a network of vesicular structures of the lipid base.
CONCLUSION: The selected Ayurvedic formulation 'anutailam' found to contain novel nano drug delivery system to deliver water soluble ingredients across barriers.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Fulltext Net charge, hydrophobicity and specific amino acids contribute to the activity of antimicrobial peptides

Jindal MH, Le CF, Mohd Yusof MY, Sekaran SD

JUMMEC, 2014;17(1):1-7.
MyJurnal

Antimicrobial peptides (AMPs) have gained increasing attention as a potential candidate in the development of novel antimicrobial agent. Designing AMPs with enhanced antimicrobial activity while reducing the cell toxicity level is desired especially against the antibiotic-resistant microbes. Various approaches towards the design of AMPs have been described and physicochemical properties of AMPs represent the primary factors determining the antimicrobial potency of AMPs. The most common parameters include net charge and hydrophobicity, which greatly influence the antimicrobial activity of AMPs. Moreover, certain amino acids would have critical importance in affecting the antimicrobial activity as well as cell cytotoxicity of AMPS. In this review, net charge, hydrophobicity, and specific amino acid residues were discussed as factors contributing to the antimicrobial activity of AMPs.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Gelatine enhances drug dispersion in alginate bilayer film via the formation of crystalline microaggregates

Thu HE, Ng SF

Int J Pharm, 2013 Sep 15;454(1):99-106.
PMID: 23856162 DOI: 10.1016/j.ijpharm.2013.06.082

In our previous study, a novel alginate-based bilayer film for slow-release wound dressings was successfully developed. We found that alginate alone yielded poor films; however, the addition of gelatine had significantly enhanced the drug dispersion as well as the physical properties. Here, an investigation of the drug-polymer interactions in the bilayer films was carried out. Drug content uniformity test and microscopy observation revealed that the addition of gelatine generated bilayer films with a homogenous drug distribution within the matrix. The FTIR and XRD data showed an increase in film crystallinity which might infer the presence of drug-polymer crystalline microaggregates in the films. DSC confirmed the drug-polymer interaction and indicated that the gelatine has no effect on the thermal behaviour of the microaggregates, suggesting the compatibility of the drug and excipients in the bilayer films. In conclusion, the addition of gelatine can promote homogenous dispersion of hydrophobic drugs in alginate films possibly through the formation of crystalline microaggregates.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Polysaccharide-anchored fatty acid liposome

Tan HW, Misran M

Int J Pharm, 2013 Jan 30;441(1-2):414-23.
PMID: 23174410 DOI: 10.1016/j.ijpharm.2012.11.013

In this study, the preparation of N-pamitoyl chitosan (ChP) anchored oleic acid (OA) liposome was demonstrated. Two different types of water-soluble ChPs with different degrees of acylation (DA) were selected for this study. The presence of ChPs on the surface of OA liposome was confirmed with their micrographs and physicochemical properties. The "peeling off" effect on the surface of the ChP-anchored OA (OAChP) liposomes was observed on the atomic force microscope micrographs and confirmed the presence of the ChPs layer on the liposome surface. The surface tension of the OAChPs liposome solution was found to be higher than that of the OA liposome solution. This result indicated the removal of OA monomer by ChPs from the air-water interface. The increase in the minimum area per headgroup (A(min)) of the OA with the presence of ChPs has further proved the interaction between OA monomer and the hydrophobic moieties of the ChPs. The ChPs anchored onto the OA monolayer increased the curvature of the OAChP liposomes monolayer and reduced the liposome size. The size of the OAChP liposomes was reduced by 30 nm as compared with the unmodified OA liposome. Results revealed that the anchored ChPs can improve the integrity and rigidity of the OA liposome.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
In vitro and in vivo evaluation of a nanofiber wound dressing loaded with melatonin

Mirmajidi T, Chogan F, Rezayan AH, Sharifi AM

Int J Pharm, 2021 Mar 01;596:120213.
PMID: 33493599 DOI: 10.1016/j.ijpharm.2021.120213

Wound healing is a complicated process that takes a long time to complete. The three-layer nanofiber wound dressing containing melatonin is highly expected to show remarkable wound repair by reducing the wound healing time. In this study, chitosan (Cs)-polycaprolactone (PCL)/ polyvinylalcohol (PVA)-melatonin (MEL)/ chitosan-polycaprolactone three-layer nanofiber wound dressing was prepared by electrospinning for melatonin sustained release. The characteristics of the wound dressing were further evaluated. The wound dressing had a high water uptake after 24 h (401%), and the water contact angle results showed that it had hydrophilicity effect that supported the cell attachment. The wound healing effect of wound dressing was examined using a full-thickness excisional model of rat skin by the local administration of MEL. The gene expressions of transforming growth factor-beta (TGF-β1), alpha-smooth muscle actin (α-SMA), collagen type I (COL1A1), and collagen type III (COL3A1) were further studied. The histopathological evaluation showed the complete regeneration of the epithelial layer, remodeling of wounds, collagen synthesis, and reduction in inflammatory cells. The NF + 20% MEL significantly increased TGF-β1, COL1A1, COL3A1, and α-SMA mRNA expressions. This wound dressing may have a considerable potential as a wound dressing to accelerate the wound healing.

Matched MeSH terms: Hydrophobic and Hydrophilic Interactions
Fulltext Graphene-based hybrid nanoparticle of doxorubicin for cancer chemotherapy

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
Fulltext Wheat Germ Agglutinin-Conjugated Disulfide Cross-Linked Alginate Nanoparticles as a Docetaxel Carrier for Colon Cancer Therapy

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

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