The long-term outcomes of vaginoplasty using acellular porcine small intestinal submucosa grafts in patients with Mayer-Rokitansky-Küster-Hauser syndrome: A case series.

OBJECTIVE: To investigate the long-term outcomes for Mayer-Rokitansky-Küster-Hauser syndrome (MRKH) patients undergoing vaginoplasty using acellular porcine small intestinal submucosa grafts (SIS). DESIGN: A case series. POPULATION: Seventy-eight MRKH syndrome patients and a post-SIS patient who delivered a baby following the world's first robot-assisted uterus transplantation. METHODS: Mayer-Rokitansky-Küster-Hauser syndrome patients were grouped based on the postoperative time and the diagnosis-surgery interval. Outcomes of sexual function and psychological status were assessed using the female sexual function index (FSFI), self-rating scale of body image (SSBI) and self-acceptance questionnaire (SAQ). Anatomical outcomes were measured by clinicians. MAIN OUTCOME MEASURES: The primary outcome was restoration of sexual function, defined by an FSFI score in the 'good' range. Anatomical and psychological outcomes were also analysed. RESULTS: Sexual function was restored in 42.3% (33/78) of patients and the total FSFI score was 23.44 ± 4.43. Three factors (body defect, recognition of physical appearance and willingness to change physical appearance scores) in the SSBI and two in the SAQ decreased as the postoperative time increased. Based on the interval between diagnosis and surgery, the total SSBI score was lower in the short-interval group than in the long-interval group (7.25 ± 5.55 versus 12.04 ± 10.21, p = 0.038). CONCLUSIONS: Nearly half of MRKH patients in our study had good long-term sexual function after SIS vaginoplasty. Sexual function and psychological status improved as postoperative time increased. In addition, reducing the diagnosis to surgery interval was associated with improved psychological function.

Profiling of triacylglycerol composition in the breast milk of Chinese mothers at different lactation stages.

Triacylglycerol (TAG) is the primary constituent of human milk fat and plays a vital role in the healthy development of infants. But few studies reported the sophisticated profile of TAG molecular species in human breast milk and its temporal changes during a prolonged lactation period. An efficient ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) method was adopted to examine TAGs. A total of 128 TAGs in 296 human breast milk samples collected during postnatal 0 to 400 days were identified. The changes in the human milk TAG profile mainly took place in the early stages of lactation (postnatal 0-45 days), and the TAG profile became stable in mature milk after 200 days of lactation. Odd chain fatty acids (OC-FAs) may be important markers for identifying human breast milk of different lactation stages. This study could provide evidence for developing safe and efficacious human-milk substitutes for children without access to human breast milk.

Physical Stability, Oxidative Stability, and Bioactivity of Nanoemulsion Delivery Systems Incorporating Lipophilic Ingredients: Impact of Oil Saturation Degree.

There is great interest in the application of a lipid-based delivery system (like nanoemulsion) to improve the bioavailability of lipophilic components. Although emulsion characteristics are believed to be influenced by oil types, there is still a lack of systematic research concentrating on the effect of oil saturation degree on the nanoemulsion quality, especially for evaluation of the bioactivity. Here, we aimed to test the effect of oil saturation degree on the physical stability, oxidative stability, and bioactivity of the designed nanoemulision system. Our findings suggest that the oxidative stability and bioactivity of a nanoemulsion incorporating tocopherol and sesamol highly depend on the oil saturation. A nanoemulsion with an oil with a high degree of unsaturation was more susceptible to oxidation, and addition of tocopherol and sesamol could retard the lipid oxidation. Sesamol exhibited better bioactivity during the experiment compared with tocopherol in the Caenorhabditis elegans (C. elegans) model. The lipid-lowering effect of tocopherol and sesamol increased with lower saturation oil groups. The antioxidant activity of tocopherol and sesamol was higher in the high saturation oil groups. Overall, the obtained data is meaningful for applications using the designed systems to deliver lipophilic ingredients.

Membrane disruptive antimicrobial potential of NK-lysin from yellow catfish (Pelteobagrus fulvidraco).

NK-lysins, a type of broad-spectrum antimicrobial peptide (AMP), act as an essential effector of innate defense against microbial attack in higher vertebrates and so in fish. The present study delineates the structural and functional characterization of NK-lysin from yellow catfish (Pelteobagrus fulvidrac) (Pelteobagrus fulvidraco). PfNK-lysin encodes a 153-residue peptide, which displays the hallmark features of other known NK-lysins with the ordered array of six well-conserved cysteine residues and five-exon/four-intron structure. It was found to be ubiquitous in tissues, being detected most abundantly in gill and head kidney. In vivo exposure to stimuli (LPS, PolyI:C, and Edwardsiella ictaluri) induced PfNK-lysin expression in head kidney and spleen. Synthetic PfNK-lysin-derived peptide exhibited in vitro bactericidal potency against both Gram-positive and Gram-negative bacteria, with the highest inhibitory effect on pathogen Edwardsiella ictaluri. Fluorescence microscopy and scanning electron microscopy further confirmed its capacity to cause damage to the bacterial plasma membrane. Taken together, these data suggest that PfNK-lysin might participate in antimicrobial defense of yellow catfish by membrane-disruptive action.

Skin test of tuberculin purified protein derivatives with a dissolving microneedle-array patch.

BACKGROUND: The tuberculin skin test (TST) is a long-established screening method for tuberculosis. However, the Mantoux technique is often difficult to reliably perform, which affects testing results and safety, which causes local skin pain and pruritus. METHODS: In this study, dissolving microneedle-array patches (MNP) were used to deliver purified protein derivative (PPD) tuberculin into the skin. The skin reaction was compared between MNP delivery and conventional injection. RESULTS: The MNP penetrated the skin easily with a thumb press, and the microneedle dissolved into the skin completely after 1 h. The storage life of MNP loaded with PPD (MNP-PPD) was 7 weeks at atmospheric pressure and room temperature. Only 1/50 dosage of PPD (approximately 0.04 IU) was needed in MNP compared with conventional injection (2 IU) in terms of skin reactivity to TST. When TST was tested in volunteers, the redness and induration of the skin were 19.7 ± 5.6 mm in TB patients, 12.6 ± 4.4 mm in LTBI (latent TB infection) patients, and 5.8 ± 2.7 mm in BCG vaccination healthy volunteers and lasted approximately 26 ± 5.4 days. When applied with MNP-PPD, the redness and induration on the skin decreased significantly to 3.1 ± 0.7 mm in TB patients and 2.0 ± 0.5 mm in LTBI, and the duration time was only 8.5 ± 1.5 days. Moreover, despite the relatively mild skin reactivity in BCG vaccination healthy volunteers with conventional injection, there was no skin reactivity in BCG vaccination healthy volunteers with MNP-PPD. CONCLUSION: In addition to being minimally invasive, needle-free, and painless, no adverse effects were attributed to the new diagnostic method, which may be of value for the safe and effective clinical administration of TB screening. When applied with MNP-PPD, an area of redness and induration greater than 2.5 mm can identify a TB-positive patient.

Combined administration on You-Gui Yin and low-dose Raloxifene partially attenuates the bone loss in ovariectomized mice through the proliferation and osteogenic differentiation of bone marrow stromal cells.

BACKGROUND: Osteoporosis is a systemic skeletal disease of fragility fractures due to the loss of mass and deterioration of the microarchitecture of bone. PURPOSE: The aim of the study was to assess the osteogenic effects and the underlying mechanisms of the combined administration of You-Gui Yin (YGY) and Raloxifene hydrochloride (RLX) in ovariectomized (OVX) mice. METHODS: First, a classic animal model was used to mimic postmenopausal osteoporosis through the removal of the ovary of mice. Second, the OVX mice were administered YGY, RLX, and YGY + RLX for 12 weeks. Next, the bone microtomographic histomorphometry and bone mineral density (BMD) were assessed by micro-CT, and the biochemical markers of procollagen type I N-terminal propeptide (P1NP) and beta-isomerized C-telopeptide (ß-CTX) in serum were assessed. Finally, primary bone marrow stromal cells (BMSCs) were isolated from the tibia and cultured to evaluate cell proliferation and osteogenic differentiation. RESULTS: The results showed that BMD on the YGY + RLX group was higher than that on the RLX group (p < 0.05) and did not have a significant difference when compared with the sham group. Notably, the YGY + RLX group had a dramatically increased trabecular number (Tb.N) compared with that of the YGY group (p < 0.05). Moreover, the BV/TV (bone volume/total volume) and Tb.N in the YGY + RLX group were higher than that in the RLX group (p < 0.05), and the Tb.Sp (trabecular separation) was lower than that in the RLX group (p < 0.05). Moreover, the serum level of P1NP from the YGY + RLX group dramatically increased when compared with that from the YGY and RLX groups (YGY group: p < 0.05; RLX groups: p < 0.01). Notably, there was no significant difference between the YGY and YGY + RLX groups. In addition, cell proliferation from the co-administration of YGY and RLX was clearly higher than a single use of YGY and RLX (p < 0.01, respectively). The ALP/BCA (alkaline phosphatase/bicinchoninic acid) in the YGY + RLX group was higher than that in the RLX group (p < 0.01). CONCLUSION: Overall, co-administered YGY and RLX could partially attenuate bone loss and were more effective than individually using either one; this outcome might be associated with the proliferation and osteogenic differentiation of BMSCs.

Research on the Transmission Characteristics of Air-Coupled Ultrasound in Double-Layered Bonded Structures.

The ultrasonic transmission spectrum in a double-layered bonded structure is related closely to its interfacial stiffness. Consequently, researching the regularity of the transmission spectrum is of significant interest in evaluating the integrity of the bonded structure. Based on the spring model and the potential function theory, a theoretical model is developed by the transfer matrix method to predict the transmission spectrum in a double-layered bonded structure. Some shift rules of the transmission peaks are obtained by numerical calculation of this model with different substrates. The results show that the resonant transmission peaks move towards a higher frequency with the increase of the normal interfacial stiffness, and each of them has different movement distances with the increasing interfacial stiffness. Indeed, it is also observed that the movement starting points of these peaks are at the specific frequency at which the thickness of either substrate plate equals an integral multiple of half a wavelength. The results from measuring the bonding specimens, which have different interfacial properties and different substrates in this experiment, are utilized to verify the theoretical analysis. Though the theory of "starting points" is not demonstrated effectively, the shift direction and distance exactly match with the result from the theoretical algorithm.

Composition and immuno-stimulatory properties of extracellular DNA from mouse gut flora.

AIM: To demonstrate that specific bacteria might release bacterial extracellular DNA (eDNA) to exert immunomodulatory functions in the mouse small intestine. METHODS: Extracellular DNA was extracted using phosphate buffered saline with 0.5 mmol/L dithiothreitol combined with two phenol extractions. TOTO-1 iodide, a cell-impermeant and high-affinity nucleic acid stain, was used to confirm the existence of eDNA in the mucus layers of the small intestine and colon in healthy Male C57BL/6 mice. Composition difference of eDNA and intracellular DNA (iDNA) of the small intestinal mucus was studied by Illumina sequencing and terminal restriction fragment length polymorphism (T-RFLP). Stimulation of cytokine production by eDNA was studied in RAW264.7 cells in vitro. RESULTS: TOTO-1 iodide staining confirmed existence of eDNA in loose mucus layer of the mouse colon and thin surface mucus layer of the small intestine. Illumina sequencing analysis and T-RFLP revealed that the composition of the eDNA in the small intestinal mucus was significantly different from that of the iDNA of the small intestinal mucus bacteria. Illumina Miseq sequencing showed that the eDNA sequences came mainly from Gram-negative bacteria of Bacteroidales S24-7. By contrast, predominant bacteria of the small intestinal flora comprised Gram-positive bacteria. Both eDNA and iDNA were added to native or lipopolysaccharide-stimulated Raw267.4 macrophages, respectively. The eDNA induced significantly lower tumor necrosis factor-α/interleukin-10 (IL-10) and IL-6/IL-10 ratios than iDNA, suggesting the predominance for maintaining immune homeostasis of the gut. CONCLUSION: Our results indicated that degraded bacterial genomic DNA was mainly released by Gram-negative bacteria, especially Bacteroidales-S24-7 and Stenotrophomonas genus in gut mucus of mice. They decreased pro-inflammatory activity compared to total gut flora genomic DNA.

Deciphering transcriptome profile of the yellow catfish (Pelteobagrus fulvidraco) in response to Edwardsiella ictaluri.

Edwardsiella ictaluri is one of the most important pathogens posing a serious threat for yellow catfish (Pelteobagrus fulvidraco), a highly valuable fish species of increasing commercial interest in China. Here, a transcriptomic strategy was undertaken to investigate the yellow catfish gene expression profile against infection by the bacterial pathogen E. ictaluri. Comparison of the transcriptome profiles between the infected and uninfected samples showed that a massive gene expression change occurred in yellow catfish following bacterial exposure. A total of 5527 differentially expressed genes (DEGs) were detected, of which 2265 showed up-regulation and 3262 down-regulation. Gene set enrichment analysis revealed the presence of canonical pathways directly linked to innate and adaptive immune response, such as pattern recognition receptor (PRR) signaling pathways, complement and coagulation cascades, as well as T-cell receptor (TCR) and B-cell receptor (BCR) signaling pathways. Additionally, 47,526 putative EST-liked simple sequence repeats (SSRs) markers were retrieved for use in genetic studies. This study establishes the first molecular clues to understand the potential mechanisms of yellow catfish resistance to E. ictaluri, thus enabling future efforts on disease control programs in this valuable aquaculture species.

De novo annotation of the immune-enriched transcriptome provides insights into immune system genes of Chinese sturgeon (Acipenser sinensis).

Chinese sturgeon (Acipenser sinensis), one of the oldest extant actinopterygian fishes with very high evolutionary, economical and conservation interest, is considered to be one of the critically endangered aquatic animals in China. Up to date, the immune system of this species remains largely undetermined with little sequence information publicly available. Herein, the first comprehensive transcriptome of immune tissues for Chinese sturgeon was characterized using Illumina deep sequencing. Over 67 million high-quality reads were generated and de novo assembled into the final set of 91,739 unique sequences. The annotation pipeline revealed that 25,871 unigenes were successfully annotated in the public databases, of which only 2002 had significant match to the existing sequences for the genus Acipenser. Overall 22,827 unigenes were categorized into 52 GO terms, 12,742 were classified into 26 KOG categories, and 4968 were assigned to 339 KEGG pathways. A more detailed annotation search showed the presence of a notable representation of immune-related genes, which suggests that this non-teleost actinopterygian fish harbors the same intermediates as in the well known immune pathways from mammals and teleosts, such as pattern recognition receptor (PRR) signaling pathway, JAK-STAT signaling pathway, complement and coagulation pathway, T-cell receptor (TCR) and B-cell receptor (BCR) signaling pathways. Additional genetic marker discovery led to the retrieval of 20,056 simple sequence repeats (SSRs) and 327,140 single nucleotide polymorphisms (SNPs). This immune-enriched transcriptome of Chinese sturgeon represents a rich resource that adds to the currently nascent field of chondrostean fish immunogenetics and furthers the conservation and management of this valuable fish.

Effect of naive and radiolabeled rhTRAIL on the cervical cancer xenografts in mice.

BACKGROUND: There is a need for novel treatments of advanced cervical cancer. We investigated the utility of recombinant human TNF-related apoptosis-inducing ligand (rhTRAIL), a molecule capable of inducing apoptosis in cancer cells, for the therapy of CasKi cervical cancer xenografts in nude mice. RESULTS: CasKi cells proved to be sensitive in vitro to rhTRAIL with an IC50 of 120 ng/ml. (125)I-tagged rhTRAIL specifically accumulated in CasKi tumors in mice with the highest uptake of 9.4% ID/g at 2 h post-injection. Both naive and 200 µCi (188)Re-tagged rhTRAIL administered in the amount of 0.35 mg/kg body weight significantly retarded CasKi tumor growth to the same extent in mice without the side effects of cisplatin chemotherapeutic control. CONCLUSION: rhTRAIL is a promising novel agent for treatment of advanced cervical cancer.

Enzymatically catalyzed synthesis of anti-blooming agent 1,3-dibehenoyl-2-oleoyl glycerol in a solvent-free system: optimization by response surface methodology.

Products rich in 1,3-dibehenoyl-2-oleoyl glycerol (BOB) triglyceride (TAG) were produced by enzymatic interesterification of high oleic acid sunflower oil (HOSO) and behenic acid methyl ester (BME) by 1,3-regiospecific lipase Lipozyme RM IM in a solvent-free system. The impact factors of enzyme load, substrate molar ratio of BME to HOSO (BME/HOSO), reaction time, reaction temperature, and pre-equilibration water activity of the enzyme on BOB content and BME conversions were investigated by single-factor experiments and then optimized using the response surface methodology (RSM). The optimum conditions were as follows: reaction temperature, 72 °C; reaction time, 7.99 h; substrate molar ratio, 2.5:1; enzyme load, 10%; and pre-equilibration water activities of the enzyme, 0.28. The results from the experiments conducted according to the predicted optimal conditions were as follows: the content of BOB was 32.76%, and the conversion of BME was 65.16%. The experimental values agreed with the predicted values, which verified the sufficiency of the quadratic regression models. After purification under the optimal short-range molecular distillation and two-step solvent fractionation, the content of BOB in the target product can reach 77.14%, indicating the great potential for industrial production of the anti-blooming agent.

MicroRNA-126 expression is decreased in cultured primary chicken hepatocytes and targets the sprouty-related EVH1 domain containing 1 mRNA.

The microRNA-126 (miR-126) is a miRNA expressed in highly vascularized tissues, and it is believed to play a role in angiogenesis by repressing sprouty-related EVH1 domain containing 1 (Spred1). In the current study, we determined the expression pattern of chicken miR-126 (gga-miR-126) and predicted and validated its target genes. The quantitative reverse-transcription (qRT) PCR analysis showed that miR-126 was expressed in various chicken tissues with the highest level in lung. In liver, the expression level of miR-126 increased from 0 to 7 wk of age. The expression of miR-126 in primary chicken hepatocytes decreased with culturing. A miR-126 binding site was predicted in the 3' UTR (untranslated region) of chicken Spred1. Dual-luciferase reporter assays indicated that miR-126 could bind to the predicted site to repress the expression of Spred1. These data validate Spred1 as a target gene of chicken miR-126. These results will help further understand the function and regulation of miR-126 and Spred1 in chickens.

The -137G>C polymorphism in interleukin-18 promoter region and cancer risk: evidence from a meta-analysis of 21 studies.

Interleukin-18 (IL-18) is a key cytokine responsible for immune response and involved in the process of cancer development. The association of -137G>C polymorphism in the promoter region of IL-18 with cancer risk is still elusive based on current genetic association studies. We performed this meta-analysis to determine whether the -137G>C polymorphism is associated with cancer risk. A comprehensive search was conducted for databases of PubMed, EMBASE, and China National Knowledge Infrastructure. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the association strength. Publication bias was detected by Egger's and Begg's test. Twenty-one eligible studies including 3,498 cancer patients and 5,222 controls were identified and analyzed. In the overall analysis, no significant association between -137G>C polymorphism and cancer risk was observed. In the sub-group analyses of ethnicities, the -137G>C polymorphism significantly increased cancer risk in Asian population (GC/CC vs. GG: OR = 1.313, 95% CI = 1.053-1.638, heterogeneity P < 0.001) but not in Caucasian population. Further stratified analyses showed that the variant -137C allele was significantly associated with increased risk of nasopharyngeal carcinoma (C vs. G: OR = 1.484, 95% CI = 1.193-1.847, heterogeneity P = 0.213). No publication bias was detected. We provide evidence that the -137G>C polymorphism in IL-18 promoter region significantly increases cancer risk in Asian population but not in Caucasian population, and the variant -137C allele is associated with increased risk of nasopharyngeal carcinoma.

Model for human milk fat substitute evaluation based on triacylglycerol composition profile.

Being the dominant components in human milk fat (HMF), triacylglycerol (TAG) composition might be the best approximation index to represent the composing characteristics of HMF. In this study, TAG composition of HMF from different lactation stages was analyzed by RP-HPLC-APCI-MS, and the establishment of a model for the precise evaluation of human milk fat substitutes (HMFSs) based on TAG composition was indirectly realized by employment of fatty acid composition and distribution and polyunsaturated fatty acid (PUFA) and TAG compositions. The model was verified by the selected fats and oils with specific chemical compositions, and the results revealed the degrees of similarity of these fats and oils in different evaluation aspects reflected their differences in corresponding chemical composition with HMF. The newly established evaluation model with TAG composition as a comparison base could provide a more accurate method to evaluate HMFSs and might have some inspirations for HMFS production in the future.

Preparation of human milk fat substitutes from palm stearin with arachidonic and docosahexaenoic acid: combination of enzymatic and physical methods.

Human milk fat substitutes (HMFSs) were prepared by a two-step process, namely, Lipozyme RM IM-catalyzed acidolysis of interesterified high-melting palm stearin with fatty acids from rapeseed oil and blending of the enzymatic product with the selected oils on the basis of the calculation model. The optimum conditions for the enzymatic reaction were a mole ratio of palm stearin/fatty acids 1:10, 60 °C, 8% enzyme load (wt % of substrates), 4 h, and 3.5% water content (wt % of enzyme); the enzymatic product contained 39.6% palmitic acid (PA), 83.7% of the fatty acids at sn-2 position were PA (sn-2 PA), and the distribution probability of PA at the sn-2 position among total PA (% sn-2 PA) was 70.5%. With the fatty acid profiles of human milk fat (HMF) as a preferable goal, a physical blending model was established for the second step to guarantee the maximum addition of selected oils. Based on the model prediction, a desirable formula constituted enzymatic product/rapeseed oil/sunflower oil/palm kernel oil/algal oil/microbial oil at a mole ratio of 1:0.28:0.40:0.36:0.015:0.017, and the final product had PA content, sn-2 PA, and %sn-2 PA at 23.5, 43.1, and 61.1%, respectively. The contents of arachidonic and docosahexaenoic acids were 0.4 and 0.3%, respectively. Relying on the total and sn-2 fatty acid compositions of HMF and "deducting score" principle, the score for the similarity between the final product and HMF was scaled as 89.2, indicating the potential as a fat substitute in infant formulas.

Human milk fat globules from different stages of lactation: a lipid composition analysis and microstructure characterization.

The physicochemical properties of human milk fat globules (MFG) at different lactation stages from Danish mothers and the microstructure changes of MFG membrane (MFGM) at varied temperatures were investigated, and the relationship between chemical composition and the microstructure of MFGM was elucidated. The fat content in MFG was found to be significantly increased as lactation progressed, and colostrum MFG had the largest mean diameter of 5.75 ± 0.81 µm and the lowest ζ potential of -5.60 ± 0.12 mV. Chemical composition analyses of MFG revealed the following: (i) Colostrum milk fat constituted higher content in PUFAs (ω-6, and long-chain ω-6 and ω-3) than transitional and mature milk fats, with the corresponding lower content of SFA in its sn-2 position. (ii) The content of polar lipids among total lipids varied during lactation course (maximized at transitional stage); however, in terms of subclasses of polar lipids, no significant change of the relative content of sphingomyelin was observed, while the content of phosphatidycholine in mature milk was higher than that in colostrum and transitional milk. (iii) Inspection of fatty acid composition in phospholipids from different lactation milk revealed no remarkable and regular changes could be generalized; and no obvious difference of the morphologies of MFGM at different lactation stages can be visualized. An investigation of the microstructure change of MFGM vs temperature demonstrated that the segregated domains became larger as temperature decreased to 4 °C, while it became smaller when increased to 37 °C. This phenomenon indicated that, in addition to sphingimyelin and cholesterol, phospholipids might also contribute to increasing the segregated domains at lower temperature, while, at elevated temperature, these domains could be diminished, most likely due to a restructuring or distributing of sphingimyelin and cholesterol.

Preparation and characterization of catalase-loaded solid lipid nanoparticles based on soybean phosphatidylcholine.

BACKGROUND: High-purity soybean phosphatidylcholine (SPC) (94%) were prepared using macroporous resin adsorption chromatography previously. Catalase is a food enzyme for promoting health and protecting against many age-related disease. Solid lipid nanoparticles (SLN) are safe immobilizing systems for efficient protein transportation to biomembranes while avoiding adverse degradation of protein. This study was aimed at developing and characterizing catalase-loaded SLN using SPC as solubilizers and stabilizing agents, to protect catalase from proteolysis. RESULTS: Catalase-loaded SLN were prepared by the double emulsification method and solvent evaporation techniques, using acetone-methylene chloride (1:1, v/v) as an organic solvent, SPC-tripalmitin as oil phase and Poloxamer 188 as a surfactant. The optimized SLN were prepared using an SPC:tripalmitin ratio of 5% (w/w), 20 s plus 30 s sonication, 20 g L⁻¹ Poloxamer 188 and 1:2 (v/v) of oily phase:outer aqueous phase ratio. The mean particle size of SLN was 296.0 ± 7.0 nm, polydispersity index range and zeta potential were 0.322-0.354 and -36.4 ± 0.6, respectively, and encapsulation efficiency reached its maximum of 77.9 ± 1.56%. Catalase, which was found to distribute between the solid lipid and inner aqueous phase, was gradually released from SLN up to 20% within 20 h. Catalase-loaded SLN had stably retained 30% of H2O2-degrading activity for at least 24 h in a proteolytic environment, while free catalase lost its activity within 1 h. CONCLUSION: Catalase can indeed be loaded in tripalmitin-based SLN using SPC as solubilizers and stabilizing agents, which protected it against proteolysis, suggesting the potential application of SPC in delivery and protection of functional food enzyme.

Preparation and characterization of catalase-loaded solid lipid nanoparticles protecting enzyme against proteolysis.

Catalase-loaded solid lipid nanoparticles (SLNs) were prepared by the double emulsion method (w/o/w) and solvent evaporation techniques, using acetone/methylene chloride (1:1) as an organic solvent, lecithin and triglyceride as oil phase and Poloxmer 188 as a surfactant. The optimized SLN was prepared by lecithin: triglyceride ratio (5%), 20-second + 30-second sonication, and 2% Poloxmer 188. The mean particle size of SLN was 296.0 ± 7.0 nm, polydispersity index range and zeta potential were 0.322-0.354 and -36.4 ± 0.6, respectively, and the encapsulation efficiency reached its maximum of 77.9 ± 1.56. Catalase distributed between the solid lipid and inner aqueous phase and gradually released from Poloxmer coated SLNs up to 20% within 20 h. Catalase-loaded SLN remained at 30% of H(2)O(2)-degrading activity after being incubated with Proteinase K for 24 h, while free catalase lost activity within 1 h.