Cellulase-assisted platelet-rich plasma release from nanofibrillated cellulose hydrogel enhances wound healing.

Platelet-rich plasma (PRP) is a source of growth factors, which are implicated in active tissue regeneration. However, after transplantation the efficacy of these bioactive compounds is often diminished due to rapid degradation and untargeted localization. For this reason, we evaluated the potential of nanofibrillated cellulose (NFC) hydrogel as a PRP carrier. NFC hydrogel is an animal-free biomaterial that, when doped with cellulase, can assist the release of PRP in a wound site. In this study, we examined the effects of 0.5% (m/v) NFC hydrogel formulations, including PRP and cellulase, on the migration and proliferation of skin cells via an in vitro scratch wound model. The suitability of the 0.8% NFC hydrogel formulations for accelerated wound healing and PRP carrying was studied in vitro in diffusion studies and in vivo in a full-thickness excisional wound model in SKH1 mice. None of the NFC hydrogel formulations with or without PRP and cellulase disturbed the normal cell behavior in vitro, and cellulase was successfully used to degrade NFC. NFC hydrogel slowed fibroblast migration rate in vitro. In vivo, NFC hydrogel treatment showed significantly enhanced re-epithelialization compared to control and supported collagen deposition. In addition, angiogenesis was significantly induced via PRP release after degrading NFC hydrogel with cellulase without abnormal host reaction. This study demonstrates the potential of NFC hydrogel with cellulase as a carrier for PRP with controlled release in future skin tissue engineering applications.

Nanofibrillar cellulose-alginate hydrogel coated surgical sutures as cell-carrier systems.

Hydrogel nanomaterials, especially those that are of non-human and non-animal origins, have great potential in biomedical and pharmaceutical sciences due to their versatility and inherent soft-tissue like properties. With the ability to simulate native tissue function, hydrogels are potentially well suited for cellular therapy applications. In this study, we have fabricated nanofibrillar cellulose-alginate (NFCA) suture coatings as biomedical devices to help overcome some of the limitations related to cellular therapy, such as low cell survivability and distribution out of target tissue. The addition of sodium alginate 8% (w/v) increased the NFCA hydrogel viscosity, storage and loss moduli by slightly under one order of magnitude, thus contributing significantly to coating strength. Confocal microscopy showed nearly 100% cell viability throughout the 2-week incubation period within and on the surface of the coating. Additionally, typical morphologies in the dual cell culture of spheroid forming HepG2 and monolayer type SK-HEP-1 were observed. Twelve out of 14 NFCA coated surgical sutures remained intact during the suturing operation with various mice and rat tissue; however, partial peeling off was observed in 2 of the coated sutures. We conclude that NFCA suture coatings could perform as cell-carrier systems for cellular based therapy and post-surgical treatment.

Independent and Combined Effects of Lactitol, Polydextrose, and Bacteroides thetaiotaomicron on Postprandial Metabolism and Body Weight in Rats Fed a High-Fat Diet.

Obesity is related to the consumption of energy-dense foods in addition to changes in the microbiome where a higher abundance of gut Bacteroidetes can be found in lean subjects or after weight loss. Lactitol, a sweet-tasting sugar alcohol, is a common sugar-replacement in foods. Polydextrose (PDX), a highly branched glucose polymer, is known to reduce energy intake. Here, we test if the combined effects of lactitol or PDX in combination with Bacteroides species will have a beneficial metabolic response in rats fed a high-fat (HF) diet. A total of 175 male Wistar rats were fed either a LF or HF diet. Bacteroides thetaiotaomicron (10(10) bacteria/animal/day) was orally administered with or without lactitol (1.6-2 g/animal/day) or PDX (2 g/animal/day) for 8 days. Postprandial blood samples, cecal digesta, and feces were collected on the last day. Measurements included: body weight, feed consumption, cecal short-chain fatty acids, fecal dry matter and heat value, blood glucose, insulin, triglyceride, and satiety hormone concentrations. Lactitol and PDX decreased the mean body weight when administered with B. thetaiotaomicron or when lactitol was administered alone. Levels of postprandial plasma triglycerides declined with lactitol and PDX when administered with B. thetaiotaomicron. For intestinal hormone release, lactitol - alone or with B. thetaiotaomicron - increased the release of gastrointestinal peptide tyrosine tyrosine (PYY) as well as the area under the curve (AUC) measured for PYY (0-8 h). In addition, levels of insulin AUC (0-8 h) decreased in the lactitol and PDX-supplemented groups. Lactitol and PDX may both provide additional means to regulate postprandial metabolism and weight management, whereas the addition of B. thetaiotaomicron in the tested doses had only minor effects on the measured parameters.

The potential of cod hydrolyzate to inhibit blood pressure in spontaneously hypertensive rats.

Hypertension is an independent yet controllable risk factor for cardiovascular diseases. Synthetic angiotensin-converting enzyme (ACE) inhibitors used to treat hypertension are often associated with adverse effects, and the interest in diet-related inhibitors is increasing. We hypothesized that North Atlantic fish hydrolysate might inhibit ACE, thus preventing hypertension. We assessed the ACE inhibitory potential of various North Atlantic fish species and evaluated the effect of dietary supplementation of fish hydrolysates on the blood pressure of spontaneously hypertensive rats. Fish samples were hydrolyzed using simulated gastrointestinal digestion, and ACE inhibitory activity was evaluated using an ACE inhibitory activity assay. In vivo anti-hypertensive effects were evaluated by administering hydrolysates of wild Atlantic cod (Gadus morhua L.), haddock (Melanogrammus aeglefinus L.), or farmed Atlantic salmon (Salmo salar L.) to 10-week-old male, spontaneously hypertensive rats for 4 weeks. The dosing was 200 mg/kg body weight for 21 days, followed by 500 mg/kg body weight for 7 days. Water and Captopril (20 mg/kg body weight) were administered as the negative and positive controls, respectively. The analyzed fish hydrolysates exhibited a 50% ACE inhibition coefficient (IC50) of 1 to 2.7 µg/mU ACE. Fish hydrolysate supplements did not significantly inhibit the increase in blood pressure during the experimental period. The group receiving cod supplement had a lower (not significant) increase in blood pressure compared to the other groups. Although further studies are necessary to verify the antihypertensive effect of cod, the results obtained in this study indicate the potential that cod hydrolysate may have in inhibiting hypertension.

Identification of metabolites of fosinopril produced by human and rat liver microsomes with liquid chromatography-mass spectrometry.

Metabolic profiles of prodrug fosinopril and pharmacologically active metabolite fosinoprilat were studied using human or rat liver microsomes and S9 fractions. Metabolites were identified by ultra high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS) using electrospray ionization in the positive and negative ion mode. They were characterized by accurate MS and MS/MS spectra and based on their different fragmentation pathways. With human liver microsomes fosinopril was metabolized via hydroxylation, glucuronidation, and hydrolysis to fosinoprilat. As expected the main metabolite was fosinoprilat and it was further hydroxylated and glucuronidated. However, these metabolites were not detected after incubation of fosinoprilat with human liver microsomes, indicating that metabolic reactions occur in sequence and fosinopril is hydrolyzed after glucuronidation or hydroxylation. With the developed UHPLC/Q-TOF-MS method once or twice hydroxylated fosinopril metabolites were detected for the first time and different regioisomers were separated. It was observed that the hydrolysis of fosinopril to fosinoprilat was more efficient with rat than with human liver microsomes, and therefore more hydroxylated fosinoprilat metabolites were detected when rat liver microsomes were used. Glucuronidation of fosinopril was not observed with rat liver microsomes.

Changes in satiety hormone concentrations and feed intake in rats in response to lactic acid bacteria.

A negative energy balance can be accomplished by reducing the caloric intake which results in an increased feeling of hunger. This physiological state is regulated by secretion of satiety hormones. The secretion of these hormones can be influenced by ingestion of e.g. fat. Fat, dairy beverage and synbiotic mixture have been found to have satiety-inducing effects in humans and rats. Thus, the aim of this study was to investigate the change of satiety hormone concentration in rats in response to feeding of fermented milks containing lactic acid bacteria. Two studies were conducted with Wistar rats randomly allocated into groups receiving Lactobacillus fermented (2 L. acidophilus, L. bulgaricus, L. salivarius and L. rhamnosus) milk. A single isocaloric oral dose with the test item or control was given to the rats. Blood samples were taken after dosing with the test product and the satiety hormones were measured. For the test groups, significant changes could be detected in PYY concentrations after 60 min, although some groups had a significant lower feed intake. In conclusion, some probiotic Lactobacillus strains may modify satiety hormones production. However, more studies are needed to evaluate their potential of prolonging satiety.

Effects of the viability of Lactobacillus rhamnosus GG on rotavirus infection in neonatal rats.

AIM: To study the effects of live and dead Lactobacillus rhamnosus GG (GG) on rotavirus infection in a neonatal rat model. METHODS: At the age of 2 d, suckling Lewis rat pups were supplemented with either live or dead GG and the treatment was continued daily throughout the experiment. At the age of 5 and 6 d the pups received oral rotavirus (RV) SA-11 strain. The pups were sacrificed at the age of 7 or 8 d by decapitation. The gastrointestinal tract was removed and macroscopic observations were done. The consistency of feces in the colon was classified using a four-tier system. RV was detected from the plasma, small intestine, colon and feces by real-time quantitative polymerase chain reaction (PCR). RESULTS: In this neonatal rat model, RV induced a mild-to-moderate diarrhea in all except one pup of the RV-inoculated rats. RV moderately reduced body weight development from day 6 onwards. On day 7, after 2 d of RV infection, live and dead GG groups gained significantly more weight than the RV group without probiotics [36% (P = 0.001) and 28% (P = 0.031), respectively]. In addition, when compared with the RV control group, both live and dead GG reduced the weight ratio of colon/animal body weight to the same level as in the healthy control group, with reductions of 22% (P = 0.002) and 28% (P < 0.001), respectively. Diarrhea increased moderately in both GG groups. However, the diarrhea incidence and severity in the GG groups were not statistically significantly different as compared with the RV control group. Moreover, observed diarrhea did not provoke weight loss or death. The RV control group had the largest amount of RV PCR-positive samples among the RV-infected groups, and the live GG group had the smallest amount. Rats receiving live GG had significantly less RV in the colon (P = 0.027) when compared with the RV control group. Live GG was also more effective over dead GG in reducing the quantity of RV from plasma (P = 0.047). CONCLUSION: Both live and dead GG have beneficial effects in RV infection. GG may increase RV clearance from the body and reduce colon swelling.

Bifidobacterium animalis ssp. lactis 420 Protects against Indomethacin-Induced Gastric Permeability in Rats.

Gastrointestinal (GI) adverse effects such as erosion and increased permeability are common during the use of nonsteroidal anti-inflammatory drugs (NSAIDs). Our objective was to assess whether Bifidobacterium animalis ssp. lactis 420 protects against NSAID-induced GI side effects in a rat model. A total of 120 male Wistar rats were allocated into groups designated as control, NSAID, and probiotic. The NSAID and probiotic groups were challenged with indomethacin (10 mg/kg(-1); single dose). The probiotic group was also supplemented daily with 10(10) CFU of B. lactis 420 for seven days prior to the indomethacin administration. The control group rats received no indomethacin or probiotic. The permeability of the rat intestine was analysed using carbohydrate probes and the visual damage of the rat stomach mucosa was graded according to severity. B. lactis 420 significantly reduced the indomethacin-induced increase in stomach permeability. However, the protective effect on the visual mucosal damage was not significant. The incidence of severe NSAID-induced lesions was, nevertheless, reduced from 50% to 33% with the probiotic treatment. To conclude, the B. lactis 420 supplementation protected the rats from an NSAID-induced increase in stomach permeability and may reduce the formation of more serious GI mucosal damage and/or enhance the recovery rate of the stomach mucosa.