微囊化吲哚美辛片剂的研讨

以明胶-CAP 为囊材,经复凝聚法制备吲哚美辛微囊,再按所筛选的最佳处方制备微囊化片剂。该片与市售片相比,体外 T_(50)延长约5.6倍,家兔体内达峰时间滞后,能明显减轻对大鼠胃的刺激性。     

静电法制备小微囊包裹成年猪胰岛的实验研究

目的　探索用静电法制备小微囊包裹成年猪胰岛细胞。方法　用自制的静电微囊发生装置、制备海藻酸钠 -多聚赖氨酸 -海藻酸钠 (APA)微囊 (微囊直径 <35 0 μm) ,包裹成年猪胰岛 ,体外检测APA小微囊猪胰岛生物活性及微囊膜的通透性 .结果　静电法制备的APA微囊直径 30 0～ 35 0 μm ,大小相对均一 .小微囊包裹成年猪胰岛后 ,每个微囊内可见 1～ 2个胰岛团 ,表面光滑 .囊内胰岛组织学结构完整 ,体外培养微囊化胰岛素分泌良好 ,葡萄糖刺激释放明显 ,显示了良好的细胞活力及微囊膜通透性 .结论　用我们自制的静电微囊发生装置能制备APA微囊包裹成年猪胰岛细胞 ,微囊直径 30 0～ 35 0 μm ,表面光滑 ,囊内猪胰岛生物活性良好     

Polymeric Microspheres Prepared by Spraying into Compressed Carbon Dioxide

Purpose. The objective was to prepare polymeric microparticles by atomizing organic polymer solutions into a spray chamber containing compressed CO₂ (PCA-process) and to study the influence of various process parameters on their morphological characteristics. Methods. The swelling of various pharmaceutically acceptable polymers [ethyl cellulose, poly(methyl methacrylate), poly(-caprolactone), poly(dl-lactide), poly(l-lactide) and poly(dl-lactide-glycolide) copolymers] in CO₂ was investigated in order to find polymers which did not agglomerate during the spraying process. Poly(l-lactide) (L-PLA) microparticles were prepared by spraying the organic polymer solution into CO₂ in a specially designed spraying apparatus. The effect of various process (pressure and temperature of the CO₂ phase, flow rate) and formulation (polymer concentration) variables on the morphology and particle size of L-PLA-microparticles was investigated. Results. Polymers with low glass transition temperatures agglomerated even at low temperatures. The formation of microparticles was favored at moderate temperatures, low polymer concentrations, high pressures and high flow rates of CO₂. High polymer concentrations and low flow rates resulted in the formation of polymeric fibers. Colloidal L-PLA particles could also be prepared with this technique in a surfactant-free environment. Initial studies on the microencapsulation of drugs resulted in low encapsulation efficiencies. Conclusions. The PCA method is a promising technique for the preparation of drug-containing microparticles. Potential advantages of this method include the flexibility of preparing microparticles of different size and morphology, the elimination of surfactants, the minimization of residual organic solvents, low to moderate processing temperatures and the potential for scale-up.     

含药树脂微囊法制备口服缓释混悬液Ⅰ.右美沙芬口服缓释混悬液

采用含药树脂微囊法制备了右美沙芬口服缓释混悬夜，研究了影响含药树脂药物吸附和释放的因素及体外释药和健康志愿者体内的药动学。结果表明该混悬液在服用12h后，尚有101．9ng／m1的有效血药浓度。     

Toxicology and carcinogenesis studies of microencapsulated citral in rats and mice.

Citral, a widely used natural ingredient, is added to foods and cosmetics as a flavoring and fragrance agent. Male and female F344/N rats and B6C3F1 mice were exposed to microencapsulated citral in the feed for 14 weeks or two years. All studies included untreated and vehicle control groups. In the 14-week studies, rats and mice were given diets containing 3,900, 7,800, 15,600, or 31,300 ppm citral. In rats, food consumption was reduced in the two highest dose groups. In mice an apparent increase in food consumption was observed, but was due to mice scattering the feed. Body weights of all treated animals were less than controls. All rats and four male mice were killed moribund in the high dose groups. In rats, forestomach and kidney lesions were observed. At the higher doses, lesions observed in the bone marrow, testes, and thymus in rats and in the ovary in mice were considered related to inanition and resultant moribundity. In the two-year studies, rats were exposed to 1,000, 2,000, or 4,000 ppm citral. Body weights were reduced in the 4,000 ppm rats. Mice were exposed to 500, 1,000, or 2,000 ppm citral. Body weights in the 1,000 and 2,000 ppm groups were reduced. No neoplasms were attributed to citral in rats or mice. Malignant lymphoma occurred with a positive trend and was significantly greater than controls in female mice in the 2,000 ppm group. However, the incidences were within the NTP historical control range and could not be clearly related to citral administration.     

简便微囊制备法——卵巢细胞微囊化的制备与功能检测

目的探讨微囊化制备在卵巢细胞体外增殖培养研究中的作用。方法将卵巢细胞分离培养并使用简便微囊制备法将卵巢细胞微囊化,观察细胞体外增生及测定培养液中雌激素和孕酮的含量,以检测卵巢细胞的内分泌功能和微囊的通透性能。结果增生培养至第6代与原代卵巢细胞雌、孕激素的分泌量相近,而且微囊化后雌、孕激素的分泌量差异无统计学意义(P>0.05)。结论体外培养的卵巢细胞有内分泌功能,微囊化后不影响其分泌物的释放。     

Lyophilised Vegetal BM 297 ATO-Inulin lipid-based synbiotic microparticles containing Bifidobacterium longum LMG 13197: design and characterisation

Abstract

This study aimed at the manufacturing and characterisation of Vegetal BM 297 ATO-inulin-Bifidobacterium longum LMG 13197 microparticles prepared by freeze drying. Emulsions containing 1%, 1.5%, 2%, 3.5% or 5% w/v inulin were prepared, with or without centrifugation before freeze drying. Morphological properties, particle size distribution, encapsulation efficiency of the microparticles and their ability to preserve viability of the enclosed B. longum LMG 13197 cells were evaluated. The microparticles produced from both formulations without a centrifugation step were irregular, porous with concavities and contained high number of bacterial cells. Formulations with or without inulin had average particle sizes of 33.4–81.0?μm with encapsulation efficiencies of 82% and 88%, respectively. Vegetal-inulin microparticles have the morphology and size that will enable their even distribution in final food products, and hence, they have the potential for use as a functional food additive because they are likely to deliver sufficient numbers of viable bacteria.     

Treatment of MPS I mice with microencapsulated cells overexpressing IDUA: effect of the prednisolone administration

Cell encapsulation, although a promising strategy to deliver therapeutic products, is hampered by immune response against biomaterials. The aim of this article is to assess the effect of prednisolone on enzyme release by microencapsulated cells implanted in vivo. Recombinant cells encapsulated were implanted in the peritoneum of wild-type mice and mucopolysaccharidosis (MPS) I mice, with or without prednisolone. Later, microcapsules were recovered for histological and enzyme analysis. Blood was collected from MPS I mice. All animals receiving prednisolone had a smaller inflammatory infiltrate. In vitro, prednisolone increased the amount of enzyme released from the recovered capsules, but this was not accompanied by an increase in the amount of circulating enzyme in vivo after 15 days. However, in 7 days, prednisolone significantly increased the amount of enzyme detected in the serum. Although prednisolone improved enzyme release in vitro and in vivo after 7 days, it was unable to maintain this effect for a longer period.     

The effect of polymer molecular weight and cell seeding density on viability of cells entrapped within PEGDA hydrogel microspheres

Abstract

Cell microencapsulation can be used in tissue engineering as a scaffold or physical barrier that provides immunoisolation for donor cells. When used as a barrier, microencapsulation shields donor cells from the host immune system when implanted for cell therapies. Maximizing therapeutic product delivery per volume of microencapsulated cells necessitates first optimising the viability of entrapped cells. Although cell microencapsulation within alginate is well described, best practices for cell microencapsulation within polyethylene glycol is still being elucidated. In this study we microencapsulate mouse preosteoblast cells within polyethylene glycol diacrylate (PEGDA) hydrogel microspheres of varying molecular weight or seeding densities to assess cell viability in relation to cell density and polymer molecular weight. Diffusion studies revealed molecule size permissible by each molecular weight PEGDA towards correlating viability with polymer mesh size. Results demonstrated higher cell viability in higher molecular weight PEGDA microspheres and when cells were seeded at higher cell densities.     

Swelling behaviour and controlled drug release from cross-linked κ-carrageenan/NaCMC hydrogel by diffusion mechanism

We studied a model system of controlled drug release using beta-carotene and κ-carrageenan/NaCMC hydrogel as a drug and a device, respectively. Different concentrations of genipin were added to crosslink the beta-carotene loaded beads by using the dripping method. Results have shown that the cross-linked beads possess lower swelling ability in all pH conditions (pH 1.2 and 7.4), and swelling ratio decreases with increasing genipin concentration. Microstructure study shows that cross-linking has enhanced the stability and structure of the beads network. Determination of diffusion coefficient for the release of encapsulated beta-carotene indicates less diffusivity when beads are cross-linked. Swelling models using adaptive neuro fuzzy show that using genipin as a cross-linker in the kC/NaCMC hydrogels affects the transport mechanism. The model shows very good agreement with the experimental data that indicates that applying ANFIS modelling is an accurate, rapid and simple way to model in such a case for controlled release applications.