Alginate-based cryogel beads loaded with urea and phosphates were fabricated by the microinjecting and cryo-cross-linking method and coated with ethyl cellulose films, and their properties were investigated. The cryogel beads had narrow diameter distributions and fracture-like supermacropores with the width of 1 to 3 μm and length up to more than 30 μm. Their porosities were from 74.9% to 92.2%, and the diameters were influenced by the microtube diameter, the injection flow velocity, and the freezing temperature. The cryogel beads had higher loading capacities of 13.4 mg phosphates and 33.2 mg urea/g wet bead, and the release rate of phosphates was much lower than that of urea. The beads with coating-films with the thickness of 3 to 8 μm had a lower release rate for phosphates than those without films. The inherent characteristic of alginate beads to be fully biodegradable makes them an interesting candidate for the bioremediation of coastal sediments.

•A novel cation exchange composite cryogel embedded with cellulose beads was prepared.•High purity lactoperoxidase (>98.0%) was obtained from bovine whey by the cryogel.•The maximum recovery of 92% was observed by stepwise elution at pH 5.8.Lactoperoxidase is one of important proteins in bovine whey and it has been known to play a key role in protection of the lactating mammary gland and the intestinal tract of newborn infants against pathogenic microorganisms. However, in industrial process the separation of this protein with a high purity is a challenging work due to the low content in whey. In this work, a cation exchange composite cryogel embedded with cellulose beads was prepared and employed to separate lactoperoxidase from bovine whey. High purity of lactoperoxidase (98.0–99.8%) was obtained with a stepwise elution using 0.075 M NaCl follow by 0.15 M and 1 M NaCl in 10 mM phosphate buffer and the maximum recovery of about 92% was obtained at pH 5.8, indicating that the present cation exchange composite cryogel could be potential and interesting in the separation of minor proteins like lactoperoxidase from bovine whey.

Delivery of poorly water-soluble compounds by use of nanosized lipid carriers has attracted much attention in pharmaceutical and therapeutic areas in recent years. However, it is difficult to formulate poorly water-soluble compound loaded lipid nanoparticles with narrow size distributions and proper drug load properties. In the present work, we introduce a precise mechanical manufacture method, the microcutting approach, to fabricate a microchannel system on a stainless steel slab, which was then assembled and employed to prepare poorly water-soluble drug loaded solid lipid nanoparticles (SLNs) by liquid flow-focusing and gas displacing techniques. A poorly water-soluble drug, puerarin, was used as the model drug, and the production of puerarin-loaded SLNs was achieved under various conditions. Particle size distribution of the obtained drug-loaded SLNs was measured by dynamic light scattering (DLS), and the particle morphology was observed by transmission electron microscopy (TEM). The state of the drug-loaded SLNs was analyzed by differential scanning calorimetry (DSC), and the drug load was determined by high-performance liquid chromatography (HPLC). The results showed that microchannels fabricated by the present mechanical microcutting method were excellent in surface quality and precise in channel sizes and shapes, which are easily scaled-up. The puerarin-loaded SLNs prepared by the present microchannel system have a narrow size distribution and the mean particle size varied with the velocities of fluids and the lipid concentration. The drug load capacity of puerarin was influenced by preparation parameters, like the flow velocities of liquids and the concentrations of lipid and puerarin. Therefore, by employing suitable preparation parameters, one can produce poorly water-soluble drug loaded SLNs with expected sizes and drug load capacities by use of microchannels fabricated by the microcutting method, which could be an effective and alternative approach for scale-up production of those new nanosized delivery systems containing poorly water-soluble drugs for potential pharmaceutical and therapeutic applications.

Dextran-hyaluronate (Dex-HA) based supermacroporous cryogel scaffolds for soft tissue engineering were prepared by free radical cryo-copolymerization of aqueous solutions containing the dextran methacrylate (Dex-MA) and hyaluronate methacrylate (HA-MA) at various macromonomer concentrations under the freezing condition. It was observed that the suitable total concentration of macromonomers for the preparation of Dex-HA cryogel scaffold with satisfied properties was 5% (w/w) at the HA-MA concentration of 1% (w/v), which was then used to produce the test scaffold. The obtained cryogel scaffold with 5% (w/w) macromonomer solution had high water permeability (5.1 × 10−12 m2) and high porosity (92.4%). The pore diameter examined by scanning electron microscopy (SEM) was in a broad range of 50–135 μm with the mean pore diameter of 91 μm. Furthermore, the cryogel scaffold also had good elastic nature with the elastic modulus of 17.47±1.44 kPa. The culture of 3T3-L1 preadipocyte within the scaffold was investigated and observed by SEM. Cells clustered on the pore walls and grew inside the scaffold indicating the Dex-HA cryogel scaffold could be a promising porous biomaterial for applications in tissue engineering.

A capillary-based model modified for characterization of monolithic cryogels is presented with key parameters like the pore size distribution, the tortuosity and the skeleton thickness employed for describing the porous structure characteristics of a cryogel matrix. Laminar flow, liquid dispersion and mass transfer in each capillary are considered and the model is solved numerically by the finite difference method. As examples, two poly(hydroxyethyl methacrylate) (pHEMA) based cryogel beds have been prepared by radical cryo-copolymerization of monomers and used to test the model. The axial dispersion behaviors, the pressure drop vs. flow rate performance as well as the non-adsorption breakthrough curves of different proteins, i.e., lysozyme, bovine serum albumin (BSA) and concanavalin A (Con A), at various flow velocities in the cryogel beds are measured experimentally. The lumped parameters in the model are determined by matching the model prediction with the experimental data. The results showed that for a given cryogel column, by using the model based on the physical properties of the cryogel (i.e., diameter, length, porosity, and permeability) together with the protein breakthrough curves one can obtain a reasonable estimate and detailed characterization of the porous structure properties of cryogel matrix, particularly regarding the number of capillaries, the capillary tortuousness, the pore size distribution and the skeleton thickness. The model is also effective with regards to predicting the flow performance and the non-adsorption breakthrough profiles of proteins at different flow velocities. It is thus expected to be applicable for characterizing the properties of cryogels and predicting the chromatographic performance under a given set of operating conditions.

•A novel cation exchange composite cryogel embedded with cellulose beads was prepared.•High purity lactoperoxidase (>98.0%) was obtained from bovine whey by the cryogel.•The maximum recovery of 92% was observed by stepwise elution at pH 5.8.Lactoperoxidase is one of important proteins in bovine whey and it has been known to play a key role in protection of the lactating mammary gland and the intestinal tract of newborn infants against pathogenic microorganisms. However, in industrial process the separation of this protein with a high purity is a challenging work due to the low content in whey. In this work, a cation exchange composite cryogel embedded with cellulose beads was prepared and employed to separate lactoperoxidase from bovine whey. High purity of lactoperoxidase (98.0–99.8%) was obtained with a stepwise elution using 0.075 M NaCl follow by 0.15 M and 1 M NaCl in 10 mM phosphate buffer and the maximum recovery of about 92% was obtained at pH 5.8, indicating that the present cation exchange composite cryogel could be potential and interesting in the separation of minor proteins like lactoperoxidase from bovine whey.