Papers by Amir M Alsharabasy
Molecular pharmaceutics, Feb 27, 2024
International Journal of Biological Macromolecules, Jan 31, 2024
ACS Pharmacology & Translational Science
ACS Applied Materials & Interfaces
Journal of Drug Delivery Science and Technology, 2019
Abstract In the present work, nanoconjugates of shRNA-plasmid and a non-viral nanoceramic vector,... more Abstract In the present work, nanoconjugates of shRNA-plasmid and a non-viral nanoceramic vector, e.g., Mg–Al layered double hydroxide (Mg-Al LDH), were synthesized and intercalated. Subsequently, these particles with an average size of 40–60 nm, were transfected into mammalian neuroblastoma cells (SH-SY5Y). The as prepared Mg–Al LDH was able to protect the incorporated shRNA-plasmid against a range of pH values, DNaseI, endonucleases, and serum components. To test the applicability of the nanoconjugate for future in-vivo studies, serum from three different model experimental animals viz, mouse, rat and guinea pig was used for the serum protection study. Additionally, we showed that prolonged storage at different temperatures does not affect the quality of the nanoconjugate. Using this nanoconjugate to transform cells, a maximum internalization of ∼26% at 24h was achieved. Lastly, we demonstrated effective and safe delivery of the plasmid by measuring GFP production and shRNA-induced knockdown of TNF alpha.
Chemical Engineering Communications, 2018
Abstract The implantation of bioactive composites for bone repair applications has recently gaine... more Abstract The implantation of bioactive composites for bone repair applications has recently gained the attention of many research groups. The present paper introduces a method for grafting of polyvinylpyrrolidone on the surface of hydroxyapatite (CaHAp) microcrystals by wet precipitation method to manufacture new composite scaffolds with suitability for bone tissue engineering. After grafting with the polymer, the degree of CaHAp crystallinity decreased, and its thermal behavior changed indicating a strong interaction between them. Homogenous clusters of CaHAp particles within the polymeric matrix were observed in combination with an increase in the roughness of the resulting structures. Bioactivity of the composites was tested using MTT assay; a higher viability of the seeded cells was observed relative to those cultured with CaHAp powder.
Biochemical Society Transactions, 2020
The extracellular matrix (ECM) dynamics in tumour tissue are deregulated compared to the ECM in h... more The extracellular matrix (ECM) dynamics in tumour tissue are deregulated compared to the ECM in healthy tissue along with disorganized architecture and irregular behaviour of the residing cells. Nitric oxide (NO) as a pleiotropic molecule exerts different effects on the components of the ECM driving or inhibiting augmented angiogenesis and tumour progression and tumour cell proliferation and metastasis. These effects rely on the concentration of NO within the tumour tissue, the nature of the surrounding microenvironment and the sensitivity of resident cells to NO. In this review article, we summarize the recent findings on the correlation between the levels of NO and the ECM components towards the modulation of tumour angiogenesis in different types of cancers. These are discussed principally in the context of how NO modulates the expression of ECM proteins resulting in either the promotion or inhibition of tumour growth via tumour angiogenesis. Furthermore, the regulatory effects o...
Journal of Materials Chemistry B
The synthesis and characterization of the biocompatible MOF NUIG4 is reported; NUIG4 possesses an... more The synthesis and characterization of the biocompatible MOF NUIG4 is reported; NUIG4 possesses an unprecedently high doxorubicin (DOX) encapsulation capacity (1955 mg DOX/g NUIG4) with a pH-controlled release mechanism.
Chitosan is a cationic polymer with different biomedical, biotechnological, environmental, indust... more Chitosan is a cationic polymer with different biomedical, biotechnological, environmental, industrial and agricultural applications. Various methods were suggested to prepare chitosan from its natural ancestor polymer, chitin, but the controlling of the molecular weight and degree of deacetylation of the resulting polymer was a problem where there is an inverse relationship between them. This study aimed at modifying the sequence of deacetylation process in combination with number of cooling/heating cycles for chitin to produce chitosans with high molecular weight as well as enhanced deacetylation. The produced chitosans were tested for their molecular weights, chemical structure, deacetylation degrees, antioxidant properties and purity. With the proposed modification of polymer deacetylation, different chitosans of different degrees of deacetylation but similar molecular weights were prepared. This may represent a more economical method for the production as well as applications of...
Summary Controversies remain over the standard procedures for the modeling of skin fibrosis and i... more Summary Controversies remain over the standard procedures for the modeling of skin fibrosis and its use in in vitro testing of different drugs. Here, we report a reproducible protocol for producing a skin fibrosis model using human dermal fibroblasts seeded in collagen hydrogel. Detailed procedures for the fabrication of cell/hydrogel constructs, fibrosis induction, protein extraction for western blotting analysis are presented along with how this model can be employed for investigating the possible anti-fibrotic functions of certain chemical compounds.
Frontiers in Bioengineering and Biotechnology
The potential biomedical applications of nanodiamond have been considered over the last few decad... more The potential biomedical applications of nanodiamond have been considered over the last few decades. However, there is still uncertainty regarding the extent to which the surface characteristics of this material can influence potential applications. The present study investigated the effects of surface characteristics alongside the prospective of improving nanodiamond production using cold plasma and microwave technologies for the surface tailoring of the nanocarbons. Numerous approaches were applied to purify, refine and modify a group of nanosized diamonds at each step of their production cycle: from the detonation soot as the initial raw material to already certified samples. The degree of surface changes were deliberately performed slowly and kept at different non-diamond carbon presence stages, non-carbon elemental content, and amount converted superficial moieties. In total, 21 treatment procedures and 35 types of nanosize diamond products were investigated. In addition cultur...
Chemical Engineering Communications
Journal of biomaterials applications, Jan 22, 2015
Polyelectrolyte complexes represent a special class of polymeric compounds consisting of stoichio... more Polyelectrolyte complexes represent a special class of polymeric compounds consisting of stoichiometric equivalents of oppositely charged polyions interacting together spontaneously to yield a complex in different forms. The present study aimed at preparing coacervates of alginate and chitosan polymers ready for casting as wound dressing films. This was based on controlling the pH of solutions and the reactions speed through controlling the rate of mixing of the polymers solutions together without using any water-miscible solvents. Alginate was modified with radiation and oxidation, and the interactions of the resulting chains and chitosan chains were tested with FTIR spectroscopy and scanning of the resulting films with SEM. This work showed the ability to prepare a complex of highly connected polymeric chains for further biomedical applications. This complex in the form of hydrogel could enhance the proliferation of cells in vitro and the healing efficiency with accelerating the w...
Biomedical Physics & Engineering Express, 2016
Wound dressings based on composites of polymers are widely used for activating the healing proces... more Wound dressings based on composites of polymers are widely used for activating the healing process, but the expression of genes related to the growth of new tissue during healing, activated by these dressings has not been widely investigated. This study examined the effects of polyelectrolyte complex (PEC) made of the alginate and chitosan biomaterials in the form of hydrogel on the healing of excision wound. This was through studying of the changes in the expression of two angiogenic genes (vascular endothelial growth factor (VEGF) and Von Willebrand factor (vWF)) during the healing progress with real time polymerase chain reaction supported by assessing the accompanied histological changes within the healing wounds. Complete healing was observed after 16 days of the hydrogel application, but no complete closure was observed for the non-treated wounds even after three weeks of healing. The VEGF expression was enhanced in the treated wounds to reach its maximum by the 7th day referring that the two polyelectrolytes within the complex could maintain the angiogenic cascade for accelerated wound closure as well as its possible usage as a marker for enhanced neo skin tissue growth. In contrast, there were low expression levels of the vWF gene in blood cells during the first week of healing of the treated wounds, which began then to increase along with the decreasing of VEGF expression which may be due to the hemostatic effects of the used complex in the wound area. This may prove the efficiency of the hydrogel with its PEC structure in the treatment of acute wounds with accelerating the supply of blood vessels for neo tissue growth.
Research article, 2019
In the present work, nanoconjugates of shRNA-plasmid and a non-viral nanoceramic vector, e.g., Mg... more In the present work, nanoconjugates of shRNA-plasmid and a non-viral nanoceramic vector, e.g., Mg–Al layered double hydroxide (LDH), were synthesized and intercalated. Subsequently, these particles with an average size of 40–60 nm, were transfected into mammalian neuroblastoma cells (SH-SY5Y). The as prepared Mg–Al LDH was able to protect the incorporated shRNA-plasmid against a range of pH values, DNaseI, endonucleases, and serum components. To test the applicability of the nanoconjugate for future in-vivo studies, serum from three different model experimental animals viz, mouse, rat and guinea pig was used for the serum protection study. Additionally, we showed that prolonged storage at different temperatures does not affect the quality of the nanoconjugate. Using this nanoconjugate to transform cells, a maximum internalization of ∼26% at 24 h was achieved. Lastly, we demonstrated effective and safe delivery of the plasmid by measuring GFP production and shRNA-induced knockdown of TNF alpha.
Review article, 2020
The fabrication of biomimetic catalysts as substituents for enzymes is
of critical interest in th... more The fabrication of biomimetic catalysts as substituents for enzymes is
of critical interest in the field due to the problems associated with the
extraction, purification, and storage of enzymes in sensing applications.
Of these mimetics, hemin/coordination polymer-based nanocomposites,
mainly hemin/metal–organic frameworks (MOF), have been developed for various biosensing applications because of the unique properties of each component, while trying to mimic the normal biological functions of heme within the protein milieu of enzymes. This critical review first discusses the different catalytic functions of heme in the body in the form of enzyme/protein structures. The properties of hemin dimerization are then elucidated with the supposed models of hemin oxidation. After that, the progress in the fabrication of hemin/MOF nanocomposites for the sensing of diverse biological molecules is discussed. Finally, the challenges in developing this type of composites are examined as well as possible proposals for future directions to enhance the sensing performance in this field further.
Review article, 2020
Correspondence: Abhay Pandit ([email protected]) The extracellular matrix (ECM) dynamics ... more Correspondence: Abhay Pandit ([email protected]) The extracellular matrix (ECM) dynamics in tumour tissue are deregulated compared to the ECM in healthy tissue along with disorganized architecture and irregular behaviour of the residing cells. Nitric oxide (NO) as a pleiotropic molecule exerts different effects on the components of the ECM driving or inhibiting augmented angiogenesis and tumour progression and tumour cell proliferation and metastasis. These effects rely on the concentration of NO within the tumour tissue, the nature of the surrounding microenviron-ment and the sensitivity of resident cells to NO. In this review article, we summarize the recent findings on the correlation between the levels of NO and the ECM components towards the modulation of tumour angiogenesis in different types of cancers. These are discussed principally in the context of how NO modulates the expression of ECM proteins resulting in either the promotion or inhibition of tumour growth via tumour angiogen-esis. Furthermore, the regulatory effects of individual ECM components on the expression of the NO synthase enzymes and NO production were reviewed. These findings support the current efforts for developing effective therapeutics for cancers.
The implantation of bioactive composites for bone repair applications has recently gained the att... more The implantation of bioactive composites for bone repair applications has recently gained the attention of many research groups. The present paper introduces a method for grafting of polyvinylpyrrolidone on the surface of hydroxyapatite (CaHAp) micro-crystals by wet precipitation method to manufacture new composite scaffolds with suitability for bone tissue engineering. After grafting with the polymer, the degree of CaHAp crystallinity decreased, and its thermal behaviour changed indicating a strong interaction between them. Homogenous clusters of CaHAp particles within the polymeric matrix were observed in combination with an increase in the roughness of the resulting structures. Bioactivity of the composites was tested using MTT assay; a higher viability of the seeded cells was observed relative to those cultured with CaHAp powder.
As a third-generation biomaterial, the bioactive glass (BG) has gained the attention of various r... more As a third-generation biomaterial, the bioactive glass (BG) has gained the attention of various research groups who have started to employ it for enhancing tissue regeneration. Most of these applications focus on bone tissue engineering based on either BG alone or BG-based composites, where the properties of the other components can improve those of the BG. Moreover, recently, the BG has become one of the important materials with ability to improve the regeneration of soft tissues. This review highlights the up-to-date advances in the different BG-based composites which have been studied in the treatment of various soft tissue injuries. These include the neuronal, muscle, lung and cardiac tissue regeneration, as well as cornea treatment. In addition, the enhancement in tissue repair due to the composite structure is discussed with comparing to the individual component structures.
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Papers by Amir M Alsharabasy
of critical interest in the field due to the problems associated with the
extraction, purification, and storage of enzymes in sensing applications.
Of these mimetics, hemin/coordination polymer-based nanocomposites,
mainly hemin/metal–organic frameworks (MOF), have been developed for various biosensing applications because of the unique properties of each component, while trying to mimic the normal biological functions of heme within the protein milieu of enzymes. This critical review first discusses the different catalytic functions of heme in the body in the form of enzyme/protein structures. The properties of hemin dimerization are then elucidated with the supposed models of hemin oxidation. After that, the progress in the fabrication of hemin/MOF nanocomposites for the sensing of diverse biological molecules is discussed. Finally, the challenges in developing this type of composites are examined as well as possible proposals for future directions to enhance the sensing performance in this field further.
of critical interest in the field due to the problems associated with the
extraction, purification, and storage of enzymes in sensing applications.
Of these mimetics, hemin/coordination polymer-based nanocomposites,
mainly hemin/metal–organic frameworks (MOF), have been developed for various biosensing applications because of the unique properties of each component, while trying to mimic the normal biological functions of heme within the protein milieu of enzymes. This critical review first discusses the different catalytic functions of heme in the body in the form of enzyme/protein structures. The properties of hemin dimerization are then elucidated with the supposed models of hemin oxidation. After that, the progress in the fabrication of hemin/MOF nanocomposites for the sensing of diverse biological molecules is discussed. Finally, the challenges in developing this type of composites are examined as well as possible proposals for future directions to enhance the sensing performance in this field further.