In the fight against cancer, controlled drug delivery systems have emerged to enhance the therapeutic efficacy and safety of anti-cancer drugs. Among these systems, mesoporous silica nanoparticles （MSNs） with a func...In the fight against cancer, controlled drug delivery systems have emerged to enhance the therapeutic efficacy and safety of anti-cancer drugs. Among these systems, mesoporous silica nanoparticles （MSNs） with a functional surface possess obvious advantages and were thus rapidly developed for cancer treatment. Many stimuli-responsive materials, such as nanopartides, polymers, and inorganic materials, have been applied as caps and gatekeepers to control drug release from MSNs. This review presents an overview of the recent progress in the production of pH-responsive MSNs based on the pH gradient between normal tissues and the tumor microenvironment. Four main categories of gatekeepers can respond to acidic conditions. These categories will be described in detail.展开更多
Stable sub 500 nm bovine serum albumin (BSA) microsphere suspensions were produced by controlled addition of acetone and ethanol to an aqueous solution of BSA, followed by stabilization process of the formed microsphe...Stable sub 500 nm bovine serum albumin (BSA) microsphere suspensions were produced by controlled addition of acetone and ethanol to an aqueous solution of BSA, followed by stabilization process of the formed microspheres at an elevated temperature. Microspheres produced by this acetone ethanol heat denaturation method were stabilized at relatively low temperatures (70～75℃) over a short period of time (20 min). The acetone ethanol heat denaturation method, in comparison with the traditional oil/ water technique for preparation of albumin microspheres, which requires high temperature (over 100℃) and longer heating time (more than 30 min) for stabilization, offers a number of advantages. This report describes the influence of process conditions, such as ratios of acetone to ethanol to BSA aqueous solution, heating time and heating temperature, on microsphere formation and their stability. A loading efficiency of 40% rose bengal was achieved. Rose bengal release rates from these microspheres in phosphate buffered saline medium at 37 ℃ were dependent on microsphere stabilities and 25% to 60% of initial loading drug were released in 15 days.展开更多
Among the various research works going on nowadays, designing of controlled release dosage form is of great importance. For the development of suitable controlled release dosage form, a proper matrix needs to be forme...Among the various research works going on nowadays, designing of controlled release dosage form is of great importance. For the development of suitable controlled release dosage form, a proper matrix needs to be formed from which the drug release generally occur by polymer swelling, polymer erosion, drug dissolution/diffusion mechanism. HPMC （hydroxy propyl methyl cellulose）, also known as hypromellose, is one of the best known cellulosic polymers used in the development of controlled released drug delivery. It is available in various grades. Cellulosic polymers are ingredients that contain units linked together which help to retain water. Due to its high water absorptive capacity, it acts as an excellent hydrophilic gel forming polymer. HPMC generally hydrates on the outer surface to form a gelatinous layer which is critical to prevent wetting and rapid drug release from the matrices. If the drug is sparingly soluble in the system, the release of drug from the system is slow and helps in formulation of controlled release dosage form. In the ophthalmic dosage form, HPMC is used as a matrix that swells and expands after absorbing water and expand the thickness of the tear film.展开更多
基金supported by the Chinese Natural Science Foundation Project (Grant No. 30970784 and 81171455)a National Distinguished Young Scholars Grant (Grant No. 31225009) from the National Natural Science Foundation of China+5 种基金the National Key Basic Research Program of China (Grant No. 2009CB930200)the Chinese Academy of Sciences (CAS) ‘Hundred Talents Program’ (Grant No. 07165111ZX)the CAS Knowledge Innovation Program, and the State HighTech Development Plan (Grant No. 2012AA020804)the ‘Strategic Priority Research Program’ of the Chinese Academy of Sciences (Grant No. XDA09030301)NIH/NIMHD 8 G12 MD007597USAMRMC W81XWH-10-1-0767 grants
文摘In the fight against cancer, controlled drug delivery systems have emerged to enhance the therapeutic efficacy and safety of anti-cancer drugs. Among these systems, mesoporous silica nanoparticles （MSNs） with a functional surface possess obvious advantages and were thus rapidly developed for cancer treatment. Many stimuli-responsive materials, such as nanopartides, polymers, and inorganic materials, have been applied as caps and gatekeepers to control drug release from MSNs. This review presents an overview of the recent progress in the production of pH-responsive MSNs based on the pH gradient between normal tissues and the tumor microenvironment. Four main categories of gatekeepers can respond to acidic conditions. These categories will be described in detail.
文摘Stable sub 500 nm bovine serum albumin (BSA) microsphere suspensions were produced by controlled addition of acetone and ethanol to an aqueous solution of BSA, followed by stabilization process of the formed microspheres at an elevated temperature. Microspheres produced by this acetone ethanol heat denaturation method were stabilized at relatively low temperatures (70～75℃) over a short period of time (20 min). The acetone ethanol heat denaturation method, in comparison with the traditional oil/ water technique for preparation of albumin microspheres, which requires high temperature (over 100℃) and longer heating time (more than 30 min) for stabilization, offers a number of advantages. This report describes the influence of process conditions, such as ratios of acetone to ethanol to BSA aqueous solution, heating time and heating temperature, on microsphere formation and their stability. A loading efficiency of 40% rose bengal was achieved. Rose bengal release rates from these microspheres in phosphate buffered saline medium at 37 ℃ were dependent on microsphere stabilities and 25% to 60% of initial loading drug were released in 15 days.
文摘Among the various research works going on nowadays, designing of controlled release dosage form is of great importance. For the development of suitable controlled release dosage form, a proper matrix needs to be formed from which the drug release generally occur by polymer swelling, polymer erosion, drug dissolution/diffusion mechanism. HPMC （hydroxy propyl methyl cellulose）, also known as hypromellose, is one of the best known cellulosic polymers used in the development of controlled released drug delivery. It is available in various grades. Cellulosic polymers are ingredients that contain units linked together which help to retain water. Due to its high water absorptive capacity, it acts as an excellent hydrophilic gel forming polymer. HPMC generally hydrates on the outer surface to form a gelatinous layer which is critical to prevent wetting and rapid drug release from the matrices. If the drug is sparingly soluble in the system, the release of drug from the system is slow and helps in formulation of controlled release dosage form. In the ophthalmic dosage form, HPMC is used as a matrix that swells and expands after absorbing water and expand the thickness of the tear film.
