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Biomedical subjects

H L Jiang

Publications and source records attributed to H L Jiang.

41 records · Page 3Linked to original sources
PubMed1982

Tissue cryopreservation and rewarming study on giant cell tumor of bone.

An attempt has been made of cryopreservation of tissue fragments from 6 GCTB surgical specimens. They have been kept in 10% DMSO or 15% glycerol medium and stored in liquid nitrogen for periods up to 180 days. Tumor cellular components survive the process of slow freezing and rapid thawing as cellular growth is successful in subsequent culture. Though certain reversible ultrastructural changes have been detected, no apparent distinction could be found in microscopic morphology, motility, growth behavior and LDH isozyme pattern between cultured cells of the cryopreserved fragments and those of the fresh ones. Electron microscopy shows that DMSO exceeds glycerol in protecting the ultrastructure of the cells. Slow cooling and rapid thawing is recommended because ice-crystals form in the intercellular space, which causes only light damage to the cells.

Bone Neoplasms↗
PubMedDate not supplied

Preparation and characterization of hCG-loaded polylactide or poly(lactide-co-glycolide) microspheres using a modified water-in-oil-in-water (w/o/w) emulsion solvent evaporation technique.

A modified w/o/w emulsion solvent evaporation technique was adopted to prepare human Chorionic Gonadotropin (hCG)-loaded polylactide (PLA) or poly(lactide-co-glycolide) (PLGA) microspheres. The effects of preparative parameters, such as stirring rate, polymer MW and concentration, and the composition of both the inner aqueous phase and oil phase etc., on hCG entrapment efficiency and microsphere characteristics were investigated. It was found that by adding 20% glycerol into the inner aqueous phase and 40% acetone into the oil phase, smooth microspheres approximately 1 microm in diameter could be produced with high hCG entrapment efficiency (>90%). In vitro release test showed a burst release of hCG from PLGA (75:25) microspheres, followed by sustained release of 55% hCG over 2 months. The initial hCG burst from PLGA microspheres increased with the glycerol concentration in the inner aqueous phase, but decreased to a low value (ca. 20%) with the addition of acetone into the oil phase, which could be attributed to the associated changes in surface morphology of the microspheres. In vivo experiments demonstrated that a single shot of hCG-loaded PLGA microspheres could produce a comparable antibody response with the inoculation of free hCG four times.

Acetone↗
PubMedDate not supplied

Bioadhesive fluorescent microspheres as visible carriers for local delivery of drugs. I: preparation and characterization of insulin-loaded PCEFB/PLGA microspheres.

Inherently fluorescent microspheres composed of a fluorescent polyanhydride, poly(p-(carboxyethylformamido) benzoic anhydride) (PCEFB), and poly(lactide-co-glycolide) (PLGA) were prepared using the water-in-oil-in-water (w/o/w) emulsion solvent evaporation technique. The effect of the PCEFB/PLGA feed ratio and composition of the oil phase on insulin entrapment and microsphere diameter was evaluated. It was found that the insulin entrapment efficiency increased with PCEFB content and acetone per cent in the oil phase. Microsphere diameter decreased as acetone was added into the oil phase. The blend of microspheres were further characterized by GPC, IR, fluorometry and SEM. Although slight degradation of PCEFB during the fabrication process was revealed by GPC and IR, PCEFB/PLGA microspheres could still be clearly visualized by either CLSM or fluorescent microscopy, which makes it possible to directly detect the microspheres by fluorometry in vivo without the need of labelling with fluorescent dyes. The surface of PCEFB/PLGA (1:2) microspheres was smooth, while PCEFB/PLGA (2:1) microspheres were observed with rough and uneven surfaces. Sustained release of insulin from the microspheres could be achieved for approximately 4 days.

Adhesiveness↗
PubMedDate not supplied

Bioadhesive fluorescent microspheres as visible carriers for local delivery of drugs. II: Uptake of insulin-loaded PCEFB/PLGA microspheres by the gastrointestinal tract.

Uptake of novel inherently fluorescent microspheres composed of a luminescent polyanhydride, poly[p-(carboxyethylformamido)-benzoic anhydride] (PCEFB), and poly(lactide-co-glycolide) (PLGA) (2:1, weight ratio) by the gastrointestinal tract was evaluated by fluorescent microscopy. Oral efficiency of the incorporated insulin also was determined by measuring reduction of plasma glucose levels after feeding diabetic rats with a single dose of the microspheres. We found that PCEFB/PLGA microspheres could adhere to the intestinal epithelium and traverse the absorptive cells. A large number of the spheres were observed in spleen, whereas few were detected in liver within the evaluated period of time. Apparent reduction of the plasma glucose levels was observed over a span of 6 h postfeeding. The unique properties of the delivery system such as biodegradability, bioadhesivity, and inherently luminescent characteristics render it an ideal "visible" tracer for monitoring oral fate of polymeric microspheres.

Adhesives↗