scholarly journals Liposomes: From Bangham to Supercritical Fluids

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1022 ◽  
Author(s):  
Paolo Trucillo ◽  
Roberta Campardelli ◽  
Ernesto Reverchon
Keyword(s):  
Encapsulation Efficiency ◽  
Operating Cost ◽  
Scale Up ◽  
Drug Carriers ◽  
Short Review ◽  
Batch Mode ◽  
Advantages And Disadvantages ◽  
Process Scale Up ◽  
Solvent Residue ◽  
Aqueous Core

Liposomes are spherical vesicles made up of an aqueous core surrounded by phospholipids. These delivery systems (DS) are largely employed as drug carriers in several industrial fields, such as pharmaceutical and nutraceutical fields. The aim of this short review is to provide a fast overview on the main fundamentals of liposomes, thought as a compact guide for researchers and students that want to approach this topic for the first time. The mini-review will focus on the definitions, production methods and characterization protocols of the liposomes produced, making a critical comparison of the main conventional and supercritical based manufacturing methods available. The literature was analyzed deeply from the first works by Dr. Bangham in 1965 to the most recent supercritical fluid applications. The advantages and disadvantages of conventional and high-pressure processes will be described in terms of solvent elimination, production at the nanometric (50–300 nm) and micrometric level (1–100 μm) and encapsulation efficiency (20–90%). The first proposed methods were characterized by a low encapsulation efficiency (20–40%), resulting in drug loss, a high solvent residue and high operating cost. The repeatability of conventional processes was also low, due to the prevalent batch mode. Supercritical-assisted methods were developed in semi-continuous layouts, resulting in an easy process scale-up, better control of liposome dimensions (polydispersity index, PDI) and also higher encapsulation efficiencies (up to 90%).

scholarly journals Core–shell hydrogel microcapsules enable formation of human pluripotent stem cell spheroids and their cultivation in a stirred bioreactor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pouria Fattahi ◽  
Ali Rahimian ◽  
Michael Q. Slama ◽  
Kihak Gwon ◽  
Alan M. Gonzalez-Suarez ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Scale Up ◽  
Bioreactor Culture ◽  
Stirred Bioreactor ◽  
Cell Spheroids ◽  
Poly Ethylene ◽  
Aqueous Core ◽  
End Stage ◽  
Stirred Bioreactors

AbstractCellular therapies based on human pluripotent stem cells (hPSCs) offer considerable promise for treating numerous diseases including diabetes and end stage liver failure. Stem cell spheroids may be cultured in stirred bioreactors to scale up cell production to cell numbers relevant for use in humans. Despite significant progress in bioreactor culture of stem cells, areas for improvement remain. In this study, we demonstrate that microfluidic encapsulation of hPSCs and formation of spheroids. A co-axial droplet microfluidic device was used to fabricate 400 μm diameter capsules with a poly(ethylene glycol) hydrogel shell and an aqueous core. Spheroid formation was demonstrated for three hPSC lines to highlight broad utility of this encapsulation technology. In-capsule differentiation of stem cell spheroids into pancreatic β-cells in suspension culture was also demonstrated.

scholarly journals Sorption enhanced gasification (SEG) of biomass for tailored syngas production with in-situ CO2 capture: Current status, process scale-up experiences and outlook

2021 ◽  
Vol 141 ◽  
pp. 110756
Author(s):  
Ashak Mahmud Parvez ◽  
Selina Hafner ◽  
Matthias Hornberger ◽  
Max Schmid ◽  
Günter Scheffknecht
Keyword(s):  
Co2 Capture ◽  
Scale Up ◽  
Current Status ◽  
Syngas Production ◽  
Process Scale Up ◽  
Process Scale ◽  
In Situ Co2 Capture

scholarly journals Preparation and Sustained-Release Performance of PLGA Microcapsule Carrier System

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1758
Author(s):  
Shuaikai Ren ◽  
Chunxin Wang ◽  
Liang Guo ◽  
Congcong Xu ◽  
Yan Wang ◽  
...  
Keyword(s):  
Controlled Release ◽  
Biomedical Applications ◽  
Encapsulation Efficiency ◽  
Drug Carriers ◽  
Optimum Conditions ◽  
Carrier System ◽  
Preparation Conditions ◽  
Encapsulation Rate ◽  
Release Drug ◽  
Release Curve

Microcapsules have been widely studied owing to their biocompatibility and potential for application in various areas, particularly drug delivery. However, the size of microcapsules is difficult to control, and the size distribution is very broad via various encapsulation techniques. Therefore, it is necessary to obtain microcapsules with uniform and tailored size for the construction of controlled-release drug carriers. In this study, emulsification and solvent evaporation methods were used to prepare a variety of ovalbumin-loaded poly (lactic-co-glycolic acid) (PLGA) microcapsules to determine the optimal preparation conditions. The particle size of the PLGA microcapsules prepared using the optimum conditions was approximately 200 nm, which showed good dispersibility with an ovalbumin encapsulation rate of more than 60%. In addition, porous microcapsules with different pore sizes were prepared by adding a varying amount of porogen bovine serum albumin (BSA) to the internal water phase. The release curve showed that the rate of protein release from the microcapsules could be controlled by adjusting the pore size. These findings demonstrated that we could tailor the morphology and structure of microcapsules by regulating the preparation conditions, thus controlling the encapsulation efficiency and the release performance of the microcapsule carrier system. We envision that this controlled-release novel microcapsule carrier system shows great potential for biomedical applications.

scholarly journals Advantages and Disadvantages of Using Magnetic Nanoparticles for the Treatment of Complicated Ocular Disorders

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1157
Author(s):  
Elena K. Schneider-Futschik ◽  
Felisa Reyes-Ortega
Keyword(s):  
Magnetic Field ◽  
Magnetic Nanoparticles ◽  
Therapeutic Efficacy ◽  
Genetic Diseases ◽  
Systemic Exposure ◽  
Drug Carriers ◽  
Three Dimensions ◽  
Target Point ◽  
Advantages And Disadvantages ◽  
Ocular Disorders

Nanomaterials provide enormous opportunities to overcome the limitations of conventional ocular delivery systems, such as low therapeutic efficacy, side effects due to the systemic exposure, or invasive surgery. Apart from the more common ocular disorders, there are some genetic diseases, such as cystic fibrosis, that develop ocular disorders as secondary effects as long as the disease progresses. These patients are more difficult to be pharmacologically treated using conventional drug routes (topically, systemic), since specific pharmacological formulations can be incompatible, display increased toxicity, or their therapeutic efficacy decreases with the administration of different kind of chemical molecules. Magnetic nanoparticles can be used as potent drug carriers and magnetic hyperthermia agents due to their response to an external magnetic field. Drugs can be concentrated in the target point, limiting the damage to other tissues. The other advantage of these magnetic nanoparticles is that they can act as magnetic resonance imaging agents, allowing the detection of the exact location of the disease. However, there are some drawbacks related to their use in drug delivery, such as the limitation to maintain efficacy in the target organ once the magnetic field is removed from outside. Another disadvantage is the difficulty in maintaining the therapeutic action in three dimensions inside the human body. This review summarizes all the application possibilities related to magnetic nanoparticles in ocular diseases.

scholarly journals Hydrogel Contact Lens for Extended Delivery of Ophthalmic Drugs

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaohong Hu ◽  
Lingyun Hao ◽  
Huaiqing Wang ◽  
Xiaoli Yang ◽  
Guojun Zhang ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Contact Lens ◽  
Contact Lenses ◽  
Drug Carriers ◽  
Soft Contact ◽  
Soft Contact Lenses ◽  
Advantages And Disadvantages ◽  
Ophthalmic Drug Delivery ◽  
Ophthalmic Drug ◽  
Polymeric Hydrogels

Soft contact lenses can improve the bioavailability and prolong the residence time of drugs and, therefore, are ideal drug carriers for ophthalmic drug delivery. Hydrogels are the leading materials of soft contact lenses because of their biocompatibility and transparent characteristic. In order to increase the amount of load drug and to control their release at the expected intervals, many strategies are developed to modify the conventional contact lens as well as the novel hydrogel contact lenses that include (i) polymeric hydrogels with controlled hydrophilic/hydrophobic copolymer ratio; (ii) hydrogels for inclusion of drugs in a colloidal structure dispersed in the contact lenses; (iii) ligand-containing hydrogels; (iv) molecularly imprinted polymeric hydrogels; (v) hydrogel with the surface containing multilayer structure for drugs loading and releasing. The advantages and disadvantages of these strategies in modifying or designing hydrogel contact lenses for extended ophthalmic drug delivery are analyzed in this paper.

scholarly journals Polyethylene encapsulatin of nitrate salt wastes: Waste form stability, process scale-up, and economics

1991 ◽  
Author(s):  
P.D. Kalb ◽  
J.H. III Heiser ◽  
P. Colombo
Keyword(s):  
Scale Up ◽  
Waste Form ◽  
Nitrate Salt ◽  
Process Scale Up ◽  
Process Scale ◽  
Form Stability

scholarly journals Evaluation of Fixed-Bed Cultures with Immobilized Lactococcus Lactis ssp. Lactis on Different Scales

2017 ◽  
Vol 11 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Rebecca Faschian ◽  
Ilyas Eren ◽  
Steven Minden ◽  
Ralf Pörtner
Keyword(s):  
Dilution Rate ◽  
Lactococcus Lactis ◽  
Scale Up ◽  
Fixed Bed ◽  
Pilot Scale ◽  
Fixed Bed Reactor ◽  
Batch Mode ◽  
Promising Alternative ◽  
Fixed Beds ◽  
Pilot Scale Reactor

Fixed-bed processes, where cells are immobilized within macroporous carriers, are a promising alternative to processes with suspended cells. A scale-up concept is presented in order to evaluate the performance as part of process design of fixed-bed processes. Therefore,Lactococcus lactiscultivation in chemostat and batch mode was compared to fixed bed cultures on three different scales, the smallest being the downscaledMultifermwith 10 mL fixed bed units, the second a 100 mL fixed-bed reactor and the third a pilot scale reactor with 1 L fixed bed volume. As expected, the volume specific lactate productivity of all cultivations was dependent on dilution rate. In suspension chemostat culture a maximum of 2.3 g·L-1·h-1was reached. Due to cell retention in the fixed-beds, productivity increased up to 8.29 g·L-1·h-1at a dilution rate of D = 1.16 h-1(corresponding to 2.4·µmax) on pilot scale. For all fixed bed cultures a common spline was obtained indicating a good scale-up performance.

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