Liposomes are used for systemic delivery of chemotherapeutic drugs to reduce their nonspecific si... more Liposomes are used for systemic delivery of chemotherapeutic drugs to reduce their nonspecific side effects. Liposomes can encapsulate hydrophilic and lipophilic drugs in the water compartment and the lipid membrane, respectively. However, typical drug loading capacity of liposomes by passive loading method is less than 1%. The low drug loading efficiency is problematic because it necessitates the use of a large amount of carrier materials that may cause undesirable biological effects. To increase drug loading in liposomes, weusedsupersaturated drug solutionswith gemcitabine (GEM) and doxorubicin (Dox) as examples. The prepared liposomes showed higher drug loading compared with passive loading, maintainedstabilityand provided sustained drug release for 48 hrs.
Paclitaxel (PTX) and gemcitabine (GEM) are often used in combination due to the synergistic antic... more Paclitaxel (PTX) and gemcitabine (GEM) are often used in combination due to the synergistic anticancer effects. PTX and GEM combination showed a synergistic effect to SKOV-3 cells at a molar ratio of 1 to 1 and in PTX → GEM sequence. Liposomes were explored as a carrier of PTX and GEM combination. We optimized the drug loading in liposomes varying the preparation method and co-encapsulated PTX and GEM in a single liposome preparation maintaining the maximum loading efficiency of each drug. However, drug release kinetics from the co-loaded liposomes (LpPG) was suboptimal because of the detrimental effect of PTX on GEM release control. Instead, a mixture of LpP and LpG, which were separately optimized according to the desired release kinetics, achieved a greater cytotoxic effect than LpPG, due to the attenuation of GEM release relative to PTX. This study illustrates that co-encapsulation in a single carrier is not always desirable for the delivery of drug combinations, when the activity depend on the dosing sequence. These combinations may benefit from the mixed liposome approach, which offers greater flexibility in controlling the ratio and release kinetics of component drugs.
Liposomes are widely used for systemic delivery of chemotherapeutic agents to reduce their nonspe... more Liposomes are widely used for systemic delivery of chemotherapeutic agents to reduce their nonspecific side effects. Gemcitabine (Gem) makes a great candidate for liposomal encapsulation due to the short half-life and non-specific side effects; however, it has been difficult to achieve liposomal Gem with high drug loading capacity. Remote loading, which uses a transmembrane pH
Nanoparticles have received attention as promising delivery system of chemotherapy for cancer tre... more Nanoparticles have received attention as promising delivery system of chemotherapy for cancer treatment. There are many mechanisms through which nanoparticles reaches the tumor site. Many nanoparticles delivery systems have been developed to solve problems associated with chemotherapeutic drugs such as solubility and stability or to increase tumor site specificity as by attachment of ligand to surface of nanoparticles. We provide a critical review about the factors affecting the delivery of nanoparticles to tumor site, mechanisms by which nanoparticles reach the tumor site, types of nanoparticles and limitation of nanomedicine.
Liposomes are used for systemic delivery of chemotherapeutic drugs to reduce their nonspecific si... more Liposomes are used for systemic delivery of chemotherapeutic drugs to reduce their nonspecific side effects. Liposomes can encapsulate hydrophilic and lipophilic drugs in the water compartment and the lipid membrane, respectively. However, typical drug loading capacity of liposomes by passive loading method is less than 1%. The low drug loading efficiency is problematic because it necessitates the use of a large amount of carrier materials that may cause undesirable biological effects. To increase drug loading in liposomes, weusedsupersaturated drug solutionswith gemcitabine (GEM) and doxorubicin (Dox) as examples. The prepared liposomes showed higher drug loading compared with passive loading, maintainedstabilityand provided sustained drug release for 48 hrs.
Paclitaxel (PTX) and gemcitabine (GEM) are often used in combination due to the synergistic antic... more Paclitaxel (PTX) and gemcitabine (GEM) are often used in combination due to the synergistic anticancer effects. PTX and GEM combination showed a synergistic effect to SKOV-3 cells at a molar ratio of 1 to 1 and in PTX → GEM sequence. Liposomes were explored as a carrier of PTX and GEM combination. We optimized the drug loading in liposomes varying the preparation method and co-encapsulated PTX and GEM in a single liposome preparation maintaining the maximum loading efficiency of each drug. However, drug release kinetics from the co-loaded liposomes (LpPG) was suboptimal because of the detrimental effect of PTX on GEM release control. Instead, a mixture of LpP and LpG, which were separately optimized according to the desired release kinetics, achieved a greater cytotoxic effect than LpPG, due to the attenuation of GEM release relative to PTX. This study illustrates that co-encapsulation in a single carrier is not always desirable for the delivery of drug combinations, when the activity depend on the dosing sequence. These combinations may benefit from the mixed liposome approach, which offers greater flexibility in controlling the ratio and release kinetics of component drugs.
Liposomes are widely used for systemic delivery of chemotherapeutic agents to reduce their nonspe... more Liposomes are widely used for systemic delivery of chemotherapeutic agents to reduce their nonspecific side effects. Gemcitabine (Gem) makes a great candidate for liposomal encapsulation due to the short half-life and non-specific side effects; however, it has been difficult to achieve liposomal Gem with high drug loading capacity. Remote loading, which uses a transmembrane pH
Nanoparticles have received attention as promising delivery system of chemotherapy for cancer tre... more Nanoparticles have received attention as promising delivery system of chemotherapy for cancer treatment. There are many mechanisms through which nanoparticles reaches the tumor site. Many nanoparticles delivery systems have been developed to solve problems associated with chemotherapeutic drugs such as solubility and stability or to increase tumor site specificity as by attachment of ligand to surface of nanoparticles. We provide a critical review about the factors affecting the delivery of nanoparticles to tumor site, mechanisms by which nanoparticles reach the tumor site, types of nanoparticles and limitation of nanomedicine.
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Papers by Hassan Tamam