Encapsulation Of Ascorbic Acid Research Articles

Electrospun PCL scaffold modified with chitosan nanoparticles for enhanced bone regeneration

The encapsulation of ascorbic acid within chitosan nanoparticles (CHNs), embedded in a fibrous structure of a dexamethasone (Dex)-loaded PCL scaffold, provides a new plan for osteogenic differentiation of mesenchymal stem cells. This electrospun PCL fibrous scaffold can release Dex, as bone differentiation initiator, and ascorbic acid, as bone differentiation enhancer, in an approximately sustained release pattern for about 2weeks. Ascorbic acid-loaded CHNs were prepared by electrospraying a mixture of chitosan and ascorbic acid, and Dex-containing PCL fibers were prepared by electrospinning a mixture of PCL and Dex. The final PCL/chitosan bilayer scaffolds were obtained by the sequential employment of electrospinning and electrospraying methods. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) confirmed that the CHNs were successfully incorporated into the fibrous PCL matrix. The improved proliferation of hMSCs cultured on the PCL/chitosan scaffolds was also verified. Osteogenic assays showed an increase in alkaline phosphatase activity and mineral deposits. The expression of bone-specific genes also confirmed the osteogenic differentiation of cells cultured on these PCL/chitosan bilayer scaffolds. Dual-drug-loaded PCL/chitosan scaffold enhanced the osteoblast differentiation of hMSC cells and can be served as a potential scaffold for bone tissue engineering.

Impact of varying hydrocolloid proportions on encapsulation of ascorbic acid by spray drying

SummaryThere has been considerable research into ascorbic acid (AA) as a food component in the human diet and disease prevention. Microencapsulation technology has a promising strategy for enhancing the stability of AA towards the carrier food. The effects of varying hydrocolloid proportions on encapsulation of AA by spray drying have been evaluated. Spray drying pilot plant scale was used to produce the microcapsules, and capillary electrophoresis has been applied to analyse the retention of AA during bread making process. To investigate the characteristics of microstructure of encapsulated AA after processing, the environmental scanning electron microscope was used to investigate the structure of microcapsules. In addition to that to measure the particle size and distribution of microcapsules, the laser beam scattering was used. The impact of varying hydrocolloids proportion on encapsulation of AA by spray drying was studied.

Enhanced Liposomal Encapsulation of Ascorbic Acid by the Liquid Crystal β-sitosteryl-β-D-glucopyranoside

β-Sitosteryl-β-D-glucopyranoside (LC) was synthesized by reacting penta-O-acetyl-β-D-glucopyranoside with β-sitosterol, followed by deacetylation with sodium methoxide. Both lyotropic and thermotropic liquid crystal properties were observed under polarized light. Its critical micellar concentration (CMC) was 8.5 × 10−6 M. The calculated HLB value was 6.24. Ascorbic acid was encapsulated in liposomes constructed with lecithin and cholesterol resulting in encapsulation efficiency (EE) of 44.1% and drug loading (DL) of 78%. The addition of LC to liposomes increased the EE to 63.0% and DL to 82%. Therefore, LC has good co-surfactant properties and could be used as encapsulation enhancer in liposomes.

Encapsulation of ascorbic acid in liposomes prepared with milk fat globule membrane-derived phospholipids

The production of nanoliposomes is considered to be an effective technology for the encapsulation and controlled release of nutraceuticals and bioactive compounds, as well as for enhancing their stability and bioavailability. Although liposomes are generally prepared with phospholipids from soy or egg, in recent years, there has been a growing interest in the health benefits and functional properties of milk fat globule membrane-derived phospholipids, as these ingredients have become commercially available. The objective of this work was to characterize nanoliposomes prepared with milk phospholipids using microfluidization, and to evaluate their encapsulation behavior using ascorbic acid as a model biomolecule. Liposomes prepared by microfluidization with milk phospholipids showed an apparent diameter of about 100 nm. The incorporation efficiencies for ascorbic acid increased as the concentration of phospholipid-rich powder increased from 5 % to 10 % (w/w). However, from 10 % to 16 % (w/w), the incorporation efficiency reached a plateau value of 26 %. There appeared to be a change in liposome structure from unilamellar to multivesicular/multilamellar vesicles with high levels of phospholipids (16 %) and a high number of passes through the microfluidizer. Storage studies showed less stable dispersions when stored at pH 3 compared with pH 7. After 7 weeks at 4 °C, liposomes stored at pH 3 and pH 7 retained 67 % of the ascorbic acid originally encapsulated, while only 30 % remained when the dispersions were stored at 25 °C. The present work demonstrated that, using microfluidization, it was possible to obtain small, unilamellar milk phospholipids liposomes stable at neutral pH protecting ascorbic acid for at least 7 weeks.

Original article: Encapsulation of ascorbic acid in amorphous maltodextrin employing extrusion as affected by matrix/core ratio and water content

SummaryAscorbic acid (AA) was encapsulated in glassy low‐dextrose equivalent maltodextrin matrix by extrusion. The effects of formulation parameters, i.e., core/matrix ratio and water content were mainly investigated on Tg of extrudate. The AA yield, AA content and water content of the products together with extrusion parameters were also determined and compared for different formulations. The Tg of extrudates containing water content from 7.860% to 10.430% ranged from 43.17 to 27.48 °C, and the Tg of extrudates which core to matrix from 1:4 to 1:8 ranged from 35.79 to 41.64 °C. AA yield of all extrudates is above 96%, and with increasing water content, there was a slight decrease in the AA yield. The increased water level and core/matrix ratio reduce specific mechanical energy and die head pressure. X‐ray diffraction and scanning electron microscopy suggested that AA was most likely molecularly dispersed within the maltodextrin indicating the miscibility of AA and maltodextrin.