Ultrasonic-microwave technique promotes the physicochemical structure of hydrogel and its release characterization of curcumin in vitro

In this study, soybean protein isolate and hawthorn pectin were mixed to prepare binary hydrogels using ultrasound and microwave techniques. Moderate treatment can not only significantly improve the mechanical strength of the hydrogel, but also increase the tightness of the internal cross-linking. The strengthening of interactions (hydrogen bonds, hydrophobic interactions, and disulfide bonds) was the main reason for this trend. Especially, the ultrasonic-microwave (80 s) treatment hydrogel possessed excellent hardness (33.426 N), water-holding capacity (98.26%), elasticity (G' = 1205 Pa), and a more homogeneous and denser microstructure. In addition, the hydrogel minimized the extent of curcumin loss (21.23%) after 5 weeks of storage. In general, the ultrasonic-microwave technique could significantly promote the physicochemical structure and curcumin bioaccessibility of hydrogels, which showed excellent market prospects in the food industry.

Preparation and properties of the persulfate gel materials and application for the remediation of 2,4-dinitrotoluene contaminated groundwater

This study aims to develop persulfate new gel sustaining-release material (PGSR) and gelatin-gel sustaining-release material (G-PGSR) that can be injected into aquifers and slowly release S₂O₈^2- to groundwater. Compatibility and miscibility of colloidal silica gels and gelatin with S₂O₈^2- were tested. Morphologies of the as-prepared PGSR and G-PGSR were observed by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FT-IR). Release characteristics of PGSR containing variable persulfate concentrations (from 1.25 wt% to 5 wt%), silica sol (from 30 wt% to 40 wt%), and gelatin (from 0.5 wt% to 2.0 wt%) were monitored. Viscosities of PGSR solution increased from 5 to 112 cP with increasing silica sol from 30 wt% to 40 wt% during the first 10 min. Viscosities of PGSR solution in 40 wt% silica sol increased to 346 cP within the 30 min and rapidly increased to 8000 cP within the next 30 min followed by the gelation phase. Gelation rates of the PGSR solution increased with increased persulfate concentrations from 1.25 wt% to 5.0 wt%. The maximum release rates achieved at 5 h in G-PGSR were 1.98 mg of S₂O₈^2- per min similar to that in PGSR. The release persulfate concentrations in G-PGSR suggested that gelatin and colloidal silica were both compatible and miscible with S₂O₈^2-. Meanwhile, the PGSR exhibits a characteristic two-phase increase in viscosity with increased silica sol concentrations, persulfate concentrations, and gelatin concentrations. Compared with the persulfate only system, the degradation efficiency of 2,4-dinitrotoluene (2,4-DNT) was achieved 91.5 % within 3 h, while 78.6 % and 66.9 % degradation efficiency were shown in PGSR and G-PGSR, respectively. The PGSR and G-PGSR both could create persistent oxidation degradation of 2,4-DNT. Results suggested that colloidal silica and gelatin could be used to create PGSR and G-PGSR for persistent oxidation in groundwater remediation.

Parameters optimization using an artificial neural networks and release characteristics of humic acids during lignite bioconversion

The bioconversion of coal at ambient conditions is a promising technology for coal processing. However, there are few examples of the optimization of processes for industrial-scale use. In this work, the optimization of process parameters affecting lignite bioconversion by an isolated fungus WF8 using an artificial neural network (ANN) combined with a genetic algorithm (GA) was carried out for modeling of humic acids (HAs) yield and parameters. Kinetic models were used to understand the release characteristics of HAs from the bioconversion of lignite. The results of the present work indicate that the optimal process parameters (OPP) are 29 °C, initial pH of 7, 180 rpm, 0.6 mmol·L^-1 of CuSO₄, 0.4 mmol L^-1 of MnSO₄, and 6.4 μmol·L^-1 of veratryl alcohol (VA). The predicted experimental data obtained by ANN is similar to the actual and the significant correlation coefficient value (R²) of 0.99 indicates that ANN has good predictability. The actual yield of HAs are 5.17 mg·mL^-1. During bioconversion, the fungus WF8 could loosen and attack the structure of lignite. The release of HAs produced by bioconversion of lignite under the OPP via diffusion and swelling is fit to zero-order model independent on concentration. This provides support for the industrial bioconversion of lignite.

The physicochemical properties and the release of sodium caseinate/ polysaccharide gum chlorophyll multiple-layer particles by rotary side-spray fluid bed technology

Multiple-layer coating technology has widely applied to the quality modification of bioactive ingredients nowadays. This research used a rotary side-spray fluid bed to manufacture chlorophyll multiple-layer particles to adjust control release characteristics. The chlorophyll extracts were coated with sodium alginate (A1) and sodium caseinate (CA1) as the primary layer on sugar spheres and the product yield was 96.98 and 96.71%, respectively. The content of chlorophyll a and b (μg/g) were 41.04 and 13.20 in A1, 47.40 and 13.68 in CA1. The Fourier-transform infrared spectroscopy confirmed the bonding change and increase stability. The CA1 was coated with sodium alginate (CA-A), sodium carboxymethylcellulose (CA-C) and xanthan gum (CA-X) as the secondary layer, which can increase coated integrity, shell strength and thermal stability. The simulated gastrointestinal fluid showed 30.11% release in the stomach and 94.27% in the intestine, which improved release control characteristics. Increased retention rate and color stability in the storage test.

Digestion of curcumin-fortified yogurt in short/long gastric residence times using a near-real dynamic in vitro human stomach

A dynamic in vitro human stomach (DIVHS), simulating the anatomical structures, peristalsis, and biochemical environments of a real stomach as practically as possible, was applied to mimic the gastric pH and emptying during yogurt digestion in short/long gastric residence times. The influences of peristalsis, dilution, and proteolysis on digesta viscosity were quantified respectively, indicating the dominant role of proteolysis and dilution. After incorporating curcumin-whey protein microparticles with targeted-release formula in yogurt, the peak curcumin release during intestinal digestion reached 43% at 120 min in the short gastric residence time and 16% at 180 min in the long gastric residence time. The change in the maximum curcumin release depended on the gastric emptying kinetics in each residence time. This emptying-kinetics dependence was reflected by the slower microparticle disintegration and proteolysis in the long gastric residence time. The dynamic reproduction of realistic gastric conditions using DIVHS helps revealing controlled release from foods.

Graft copolymer of sodium carboxymethyl cellulose and polyether polyol (CMC-g-TMN-450) improves the crosslinking degree of polyurethane for coated fertilizers with enhanced controlled release characteristics

Novel superhydrophobic sodium carboxymethyl cellulose (CMC) modified polyurethane (MPU) was developed as the membrane material for controlled-release fertilizer (CRF) by cross-linking polymerization of 4,4'-diphenylmethane diisocyanate (MDI) and CMC-based modified polyol (CMP) which was made by grafting CMC onto polyether polyol (TMN-450). The modified polyurethane coated fertilizer (MPUCF) was prepared by using MPU as the membrane material through a fluidized bed device. Analysis results of ¹³C NMR showed that the coatings of PUCF and MPUCF were prepared by connecting hydroxyl to isocyanate groups to form a carbamate. MPU had lower water absorption rates than PU, and MPUCF coating showed excellent hydrophobicity. Scanning electron microscope (SEM) revealed that MPUCF coating surface was much more smooth and flat than that of PUCF. Furthermore, the nitrogen (N) release longevity of MPUCF can increased to 140 days when the coating rate was 5%. It is concluded that MPU was an excellent superhydrophobic coating material for CRF.

Influence of PLGA molecular weight distribution on leuprolide release from microspheres

Poly (lactide-co-glycolide) (PLGA) is a biodegradable copolymer used in many long-acting drug products. The objective of the present study was to investigate the influence of polymer molecular weight distribution differences of PLGA on the in vitro release profile of leuprolide acetate microspheres. Eight microsphere formulations were prepared using the same manufacturing process but with different PLGA polymers. The physicochemical properties (drug loading, particle size and morphology) as well as the in vitro release profiles of the prepared microspheres were evaluated using a sample-and-separate method. The amount of burst release increased with increasing amount of low molecular weight fractions of PLGA, indicating that the drug release profiles appeared to be affected not only by the average molecular weight but also the molecular weight distribution of PLGA. In conclusion, quality control of the molecular weight distribution of PLGA as well as the weight average molecular weight is highly desirable in order to control the burst release.

Release characteristics of enoxaparin sodium-loaded polymethylmethacrylate bone cement

BACKGROUND

This study aimed to prepare the polymethylmethacrylate (PMMA) bone cement release system with different concentrations of enoxaparin sodium (ES) and to investigate the release characteristics of ES after loading into the PMMA bone cement.

METHODS

In the experimental group, 40 g Palacos®R PMMA bone cement was loaded with various amount of ES 4000, 8000, 12,000, 16,000, 20,000, and 24,000 AXaIU, respectively. The control group was not loaded with ES. Scanning electron microscopy (SEM) was used to observe the surface microstructure of the bone cement in the two groups. In the experiment group, the mold was extracted continuously with pH7.4 Tris-HCL buffer for 10 days. The extract solution was collected every day and the anti-FXa potency was measured. The experiment design and statistical analysis were conducted using a quantitative response parallel line method.

RESULTS

Under the SEM, it was observed that ES was filled in the pores of PMMA bone cement polymer structure and released from the pores after extraction. There was a burst effect of the release. The release amount of ES on the first day was 0.415, 0.858, 1.110, 1.564, 1.952, and 2.513, respectively, from the six groups with various ES loading amount of 4000, 8000, 12,000, 16,000, 20,000, and 24,000 AXaIU, all reaching the peak of release on the first day. The release decreased rapidly on the next day and entered the plateau phase on the fourth day.

CONCLUSION

The prepared ES-PMMA bone cement has high application potential in orthopedic surgery. ES-PMMA bone cement shows good drug release characteristics. The released enoxaparin sodium has a local anti-coagulant effect within 24 h after application, but it will not be released for a long time, which is complementary to postoperative anti-coagulation therapy.

Investigation into the co-pyrolysis behaviors of cow manure and coal blending by TG-MS

In this study, the co-pyrolysis characteristics of cow manure (CM) and Meihuajing bituminous coal (MHJ) blends were investigated in detail. The mass loss behavior and gas evolution characteristics of the blends were analyzed online by thermogravimetry-mass spectrometry (TG-MS), and kinetic analysis was performed. The results demonstrate that the addition of CM to the MHJ increases the reactivity of blends, indicating that interaction between the CM and MHJ occurred during co-pyrolysis. For conventional gases, the release order of gases during CM and MHJ blend pyrolysis is H₂O, CO₂, CO, CH₄, H₂. For sulfur-containing gases, with increasing proportion of CM, the emissions of H₂S, COS, and C₄H₄S increase and that of SO₂ decrease, and the release temperature interval shifts to lower directions. The Coats & Redfern model was used, an increase of activation energy with CM addition was observed. The optimum blending ratio based on the lowest activation energy is CM:MHJ = 1:3 and the activation energy is 41.9 kJ/mol.

Polymeric micelles for enhanced Photofrin II ® delivery, cytotoxicity and pro-apoptotic activity in human breast and ovarian cancer cells

BACKGROUND

Searching for photodynamic therapy (PDT) - effective nanocarriers which enable a photosensitizer to be selectively delivered to tumor cells with enhanced bioavailability and diminished dark cytotoxicity is of current interest. The main objective of this study is to evaluate newly designed mixed polymeric micelles based on Pluronics P123 and F127 for the improved delivery of Photofrin II(®) (Ph II(®)) to circumvent unfavorable effects overcoming multidrug resistance (MDR) in tumor cells - in breast MCF-7/WT (caspase-3 deficient) and ovarian SKOV-3 (resistant to chemotherapy).

METHODS

Ph II(®)-loaded micelles were obtained and analyzed for size and morphology, solubilization efficiency, physical stability and in vitro drug release. Intracellular uptake, reactive oxygen species (ROS) generation, mitochondrial oxidoreductive potential and proapoptotic activity (TUNEL assay) studies were evaluated in the examined cancer cells. The preliminary biocompatibility characteristics of all nanocarriers was determined by assessment of their hemolytic activity in human erythrocytes and dark toxicity in cancer cells.

RESULTS

Dynamic light scattering (DLS) and atomic force microscopy (AFM) confirmed that almost monodisperse, sphere-shaped and nanosized (DH<20 nm) carriers were developed. Biological studies after photodynamic reaction (PDR) with encapsulated Ph II(®) revealed increased ROS level, malondialdehyde (MDA) concentration and protein damage in SKOV-3 and MCF-7/WT cells in comparison to treatment with free Ph II(®). Numerous apoptotic cells were detected after nano-therapy in both cell lines, with observed significant morphological disorders in ovarian cancer cells. In the case of encapsulated Ph II(®) only negligible disruption of human erythrocytes and cancer cells was observed.

CONCLUSIONS

The obtained biocompatible long-lasting nanocarriers significantly enhance the Photofrin II(®) photodynamic effect and apoptosis in both SKOV-3 and MCF-7/WT cell lines.

Acceleration of re-endothelialization and inhibition of neointimal formation using hybrid biodegradable nanofibrous rosuvastatin-loaded stents

Incomplete endothelialization and neointimal hyperplasia of injured arteries can cause acute and late stent thromboses. This work develops hybrid stent/biodegradable nanofibers for the local and sustained delivery of rosuvastatin to denuded artery walls. Biodegradable nanofibers were firstly prepared by dissolving poly(D,L)-lactide-co-glycolide and rosuvastatin in 1,1,1,3,3,3-hexafluoro-2-propanol. The solution was then electrospun into nanofibrous tubes, which were mounted onto commercially available bare-metal stents. The in vitro release rates of the pharmaceuticals from the nanofibers were determined using an elution method and a high-performance liquid chromatography assay. The experimental results thus obtained suggest that the biodegradable nanofibers released high concentrations of rosuvastatin for four weeks. The effectiveness of the local delivery of rosuvastatin in reducing platelets was studied. The tissue inflammatory reaction caused by the hybrid stents that were used to treat diseased arteries was also documented. The proposed hybrid stent/biodegradable rosuvastatin-loaded nanofibers contributed substantially to the local and sustainable delivery of a high concentration of drugs to promote re-endothelialization, improve endothelial function, reduce inflammatory reaction, and inhibit neointimal formation of the injured artery. The results of this work provide insight into how patients with a high risk of stent restenosis should be treated for accelerating re-endothelialization and inhibiting neointimal hyperplasia.