The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Peter C Ford - One of the best experts on this subject based on the ideXlab platform.
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polychromophoric metal complexes for generating the bioregulatory Agent nitric oxide by single and two photon excitation
Accounts of Chemical Research, 2008Co-Authors: Peter C FordAbstract:In order to deliver a Bioactive Agent to a physiological location, it is important to be able to regulate precisely the location and the dosage. Such exquisite control can easily be envisioned for a photochemical drug that is active toward release of the desired Bioactive Agent upon irradiation of a specific tissue site. These materials should be thermally stable but reactive under excitation at visible (vis) or near-infrared (NIR) wavelengths where tissue transmission is optimal. Two photon excitation (TPE) is of special interest, since the use of focused laser pulses to activate release could provide 3D spatial control in therapeutic applications. This Account describes the preparation and photochemistry of a series of transition metal complexes designed to release the simple bioregulatory compound nitric oxide upon vis or NIR excitation. In order to enhance the light gathering capability of such compounds, we have attached chromophores with high single- or two-photon absorption cross sections to severa...
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polychromophoric metal complexes for generating the bioregulatory Agent nitric oxide by single and two photon excitation
Accounts of Chemical Research, 2008Co-Authors: Peter C FordAbstract:In order to deliver a Bioactive Agent to a physiological location, it is important to be able to regulate precisely the location and the dosage. Such exquisite control can easily be envisioned for a photochemical drug that is active toward release of the desired Bioactive Agent upon irradiation of a specific tissue site. These materials should be thermally stable but reactive under excitation at visible (vis) or near-infrared (NIR) wavelengths where tissue transmission is optimal. Two photon excitation (TPE) is of special interest, since the use of focused laser pulses to activate release could provide 3D spatial control in therapeutic applications. This Account describes the preparation and photochemistry of a series of transition metal complexes designed to release the simple bioregulatory compound nitric oxide upon vis or NIR excitation. In order to enhance the light gathering capability of such compounds, we have attached chromophores with high single- or two-photon absorption cross sections to several photochemical NO precursors. For example, the iron nitrosyl clusters Fe2(mu-SR)2(NO)4 (Roussin's red esters) have been prepared with various chromophores as pendant groups, an example being the protoporphyrin XI derivative illustrated here. Direct excitation into the vis absorbing Q bands of the porphyrin leads to enhanced rates of NO generation from the Fe/S/NO cluster owing to the larger rate of light absorption by that antenna. Furthermore, femtosecond pulsed laser NIR excitation of the same compound at 810 nm (a spectral region where no absorption bands are apparent) leads to weak emission at approximately 630 nm and generation of NO, both effects providing evidence of a TPE mechanism. Roussin's red esters with other chromophores described here are even more effective for TPE-stimulated NO release. Another photochemical NO precursor discussed is the Cr(III) complex trans-Cr(L)(ONO)2(+) where L is a cyclic tetraamine such as cyclam. When L includes a chromophore tethered to the ligand backbone, excitation of that functionality results in energy transfer to the spin-forbidden ligand field double states and light-stimulated release of NO. We are working to develop systems where L is attached to a semiconductor nanoparticle as the antenna. In this context, we have shown that electrostatic assemblies are formed between the anionic surface of water-soluble CdSe/ZnS core/shell quantum dots (QDs) and Cr(L)(ONO)2(+) cations via an ion-pairing mechanism. Photoexcition of such modified QDs leads to markedly enhanced NO generation and suggests promising applications of such nanomaterials as photochemical drugs.
Wingfu Lai - One of the best experts on this subject based on the ideXlab platform.
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a self indicating cellulose based gel with tunable performance for Bioactive Agent delivery
Journal of Drug Delivery Science and Technology, 2021Co-Authors: Wingfu Lai, Dayong Gui, Mangin Wong, Aaron Doring, Andrey L Rogach, Wing Tak WongAbstract:Abstract Development of carriers with tunable properties can enhance the controllability of the process of Bioactive Agent delivery. This study reports a self-indicating gel fabricated from a cellulose-based derivative, designated as CT, for controlled release of the loaded Bioactive Agent. By increasing the concentration of CT, the swelling and erosion rates of the gel are significantly reduced, with the encapsulation efficiency and release sustainability of the gel being substantially enhanced. Such changes in delivery performance can be manifested as changes in the intensity of intrinsic luminescence of the gel, enabling the gel to display self-indicating capacity. By using paclitaxel as a model Agent, the gel is demonstrated in vivo to effectively reduce the systemic toxicity of the administered Agent. Along with its excitation wavelength-dependent emission tunability which allows the wavelength of the excitation source to be changed for convenience and need, our gel shows high potential to be exploited as a self-indicating carrier for delivery of Bioactive Agents.
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property tuneable microgels fabricated by using flow focusing microfluidic geometry for Bioactive Agent delivery
Pharmaceutics, 2021Co-Authors: Wingfu Lai, Wing Tak WongAbstract:Gelatine methacryloyl (GM) shows high biocompatibility and is extensively used in tissue engineering; however, few works have explored the use of GM in Bioactive Agent delivery. This study adopts a microfluidic approach involving the use of flow-focusing microfluidic geometry for microgel fabrication. This approach generates highly monodisperse microgels whose size can be tuned by altering various fabrication conditions (including the concentration of the gel-forming solution and the flow rates of different phases). By using tetracycline hydrochloride as a model Agent, the fabricated microgels enable prolonged Agent release, with the encapsulation efficiency being around 30–40% depending on the concentration of the gel-forming solution. Along with their negligible cytotoxicity, our microgels show the potential to serve as carriers of Bioactive Agents for food and pharmaceutical applications.
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a gel forming clusteroluminogenic polymer with tunable emission behavior as a sustained release carrier enabling real time tracking during Bioactive Agent delivery
Applied Materials Today, 2020Co-Authors: Wingfu Lai, Eric M Huang, Wing Tak WongAbstract:Abstract Sustained-release carriers with intrinsic luminescence exhibit the potential to combine imaging with Bioactive Agent delivery in practice. This study reports the synthesis and properties of CT, which is a gel-forming and highly tunable non-conjugated polymer with intrinsic luminescence. Owing to the excitation wavelength-dependent emission tunability of CT, optical imaging can be performed in a wide range of excitation wavelengths. This study is the first proof-of-concept study successfully integrating the property of clusterization-triggered emission into carrier design for combining imaging with Bioactive Agent delivery. By using cancer therapy as a practical example, our results demonstrate that CT is a depot system that cannot only enhance in vivo antitumor efficacy but can also allow its location and gelation process to be tracked in real time by giving an intrinsic blue-colored fluorescence signal. Together with its high biocompatibility, CT shows high practical potential for executing self-illuminating therapy to tackle cancer.
Milton Franklin A Benial - One of the best experts on this subject based on the ideXlab platform.
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spectroscopic and molecular docking studies on n n di tert butoxycarbonyl boc 2 amino pyridine a potential Bioactive Agent for lung cancer treatment
Journal of Molecular Structure, 2017Co-Authors: Mohamed R Asath, R Premkumar, T Mathavan, Milton Franklin A BenialAbstract:Abstract Potential energy surface scan was performed and the most stable molecular structure of the N , N -di- tert -butoxycarbonyl (Boc)-2-amino pyridine (DBAP) molecule was predicted. The most stable molecular structure of the molecule was optimized using B3LYP method with cc-pVTZ basis set. Anticancer activity of the DBAP molecule was evaluated by molecular docking analysis. The structural parameters and vibrational wavenumbers were calculated for the optimized molecular structure. The experimental and theoretical wavenumbers were assigned and compared. Ultraviolet–Visible spectrum was simulated and validated experimentally. The molecular electrostatic potential surface was simulated and Fukui function calculations were also carried out to investigate the reactive nature of the DBAP molecule. The natural bond orbital analysis was also performed to probe the intramolecular interactions and confirm the bioactivity of the DBAP molecule. The molecular docking analysis reveals the better inhibitory nature of the DBAP molecule against the epidermal growth factor receptor ( EGFR ) protein which causes lung cancer. Hence, the present study unveils the structural and Bioactive nature of the title molecule. The DBAP molecule was identified as a potential inhibitor against the lung cancer which may be useful in further development of drug designing in the treatment of lung cancer.
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structural spectroscopic and molecular docking studies on 2 amino 3 chloro 5 trifluoromethyl pyridine a potential Bioactive Agent
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2017Co-Authors: Mohamed R Asath, R Premkumar, T Mathavan, Milton Franklin A BenialAbstract:The most stable, optimized structure of the 2-amino-3-chloro-5-trifluoromethyl pyridine (ACTP) molecule was predicted by the density functional theory calculations using the B3LYP method with cc-pVQZ basis set. Antitumor activity of the ACTP molecule was evaluated by molecular docking analysis. The structural parameters and vibrational wavenumbers were calculated for the optimized molecular structure. The experimental and theoretical vibrational wavenumbers were assigned and compared. Ultraviolet-visible spectrum was simulated and validated experimentally. The molecular electrostatic potential surface was simulated. Frontier molecular orbitals and related molecular properties were computed and further density of states spectrum was simulated. The natural bond orbital analysis was also performed to confirm the bioactivity of the ACTP molecule. The molecular docking analysis reveals the better inhibitory nature of the ACTP molecule against the colony-stimulating factor 1 (CSF1) gene which causes tenosynovial giant-cell tumor. Hence, the ACTP molecule can act as a potential inhibitor against tenosynovial giant-cell tumor.
Wing Tak Wong - One of the best experts on this subject based on the ideXlab platform.
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a self indicating cellulose based gel with tunable performance for Bioactive Agent delivery
Journal of Drug Delivery Science and Technology, 2021Co-Authors: Wingfu Lai, Dayong Gui, Mangin Wong, Aaron Doring, Andrey L Rogach, Wing Tak WongAbstract:Abstract Development of carriers with tunable properties can enhance the controllability of the process of Bioactive Agent delivery. This study reports a self-indicating gel fabricated from a cellulose-based derivative, designated as CT, for controlled release of the loaded Bioactive Agent. By increasing the concentration of CT, the swelling and erosion rates of the gel are significantly reduced, with the encapsulation efficiency and release sustainability of the gel being substantially enhanced. Such changes in delivery performance can be manifested as changes in the intensity of intrinsic luminescence of the gel, enabling the gel to display self-indicating capacity. By using paclitaxel as a model Agent, the gel is demonstrated in vivo to effectively reduce the systemic toxicity of the administered Agent. Along with its excitation wavelength-dependent emission tunability which allows the wavelength of the excitation source to be changed for convenience and need, our gel shows high potential to be exploited as a self-indicating carrier for delivery of Bioactive Agents.
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property tuneable microgels fabricated by using flow focusing microfluidic geometry for Bioactive Agent delivery
Pharmaceutics, 2021Co-Authors: Wingfu Lai, Wing Tak WongAbstract:Gelatine methacryloyl (GM) shows high biocompatibility and is extensively used in tissue engineering; however, few works have explored the use of GM in Bioactive Agent delivery. This study adopts a microfluidic approach involving the use of flow-focusing microfluidic geometry for microgel fabrication. This approach generates highly monodisperse microgels whose size can be tuned by altering various fabrication conditions (including the concentration of the gel-forming solution and the flow rates of different phases). By using tetracycline hydrochloride as a model Agent, the fabricated microgels enable prolonged Agent release, with the encapsulation efficiency being around 30–40% depending on the concentration of the gel-forming solution. Along with their negligible cytotoxicity, our microgels show the potential to serve as carriers of Bioactive Agents for food and pharmaceutical applications.
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a gel forming clusteroluminogenic polymer with tunable emission behavior as a sustained release carrier enabling real time tracking during Bioactive Agent delivery
Applied Materials Today, 2020Co-Authors: Wingfu Lai, Eric M Huang, Wing Tak WongAbstract:Abstract Sustained-release carriers with intrinsic luminescence exhibit the potential to combine imaging with Bioactive Agent delivery in practice. This study reports the synthesis and properties of CT, which is a gel-forming and highly tunable non-conjugated polymer with intrinsic luminescence. Owing to the excitation wavelength-dependent emission tunability of CT, optical imaging can be performed in a wide range of excitation wavelengths. This study is the first proof-of-concept study successfully integrating the property of clusterization-triggered emission into carrier design for combining imaging with Bioactive Agent delivery. By using cancer therapy as a practical example, our results demonstrate that CT is a depot system that cannot only enhance in vivo antitumor efficacy but can also allow its location and gelation process to be tracked in real time by giving an intrinsic blue-colored fluorescence signal. Together with its high biocompatibility, CT shows high practical potential for executing self-illuminating therapy to tackle cancer.
Marek Rychter - One of the best experts on this subject based on the ideXlab platform.
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progress and perspectives in Bioactive Agent delivery via electrospun vascular grafts
RSC Advances, 2017Co-Authors: Marek Rychter, Anna Baranowskakorczyc, Janina LulekAbstract:The review discusses the progress in the design and synthesis of Bioactive Agents incorporated into vascular grafts obtained by the electrospinning process. Electrospun fibers can be applied as an artificial extracellular matrix for tissue engineering and drug delivery, improving tissue regeneration and therapeutic outcomes. A large number of active substances are loaded into the fibers, such as growth factors, heparin, NO donors, statins, antibiotics or anti-inflammatory Agents. There are various methods for Bioactive substance incorporation including direct blending, emulsion, and coaxial electrospinning as well as covalent and non-covalent binding of the Bioactive molecules to the fiber surface. The release mechanism of the drug depends on the synthesis route, active substance properties, and polymer matrix nature. The electrospun materials represent a very promising building block for the fabrication of effective vascular prosthesis in the near future.