Healthy Rat Model Research Articles

Metabolomic profile of cerebral tissue after acoustically-mediated blood-brain barrier opening in a healthy rat model: a focus on the contralateral side.

Microbubble (MB)-assisted ultrasound (US) is an innovative modality for the non-invasive, targeted, and efficient delivery of therapeutic molecules into the brain. Previously, we reported the first metabolomic signature of blood-brain barrier opening (BBBO) induced by MB-assisted US. In the present study, the neurometabolic consequences of acoustically-mediated BBBO on cerebral tissue were investigated using multimodal metabolomics approaches. Sinusoid US waves (1 MHz, peak negative pressure 0.6 MPa, burst length 10 ms, total treatment time 30 s, MB bolus dose 0.7 × 105 MBs/g) were applied on the rats' right striatum (ipsilateral side). Brain was collected and both striata were then dissected 3 h, 2 days, and 1 week after BBBO. After tissue preparation, the samples were analyzed using nuclear magnetic resonance spectrometry (NMRS) and high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Our findings showed a slight disruption of metabolic pathways in contralateral striata of animals. Analyses of metabolic pathways indicated changes in amino acid metabolisms. In addition, tryptophan derivate dosages revealed the perturbation of a central metabolite of the kynurenine pathway (i.e., 3-hydroxy-kynurenine). In conclusion, the acoustically-mediated BBBO of the ipsilateral cerebral hemisphere induced significant change in metabolism of contralateral one.

Regional variations in hyperpolarized 129Xe lung MRI: Insights from CSI-CSSR and CSSR in healthy and irradiated rat models.

To compare pulmonary function metrics obtained with hyperpolarized xenon-129 (HXe) MRS, using chemical shift saturation recovery (CSSR) and CSI-CSSR, in healthy rats and a rat model of radiation-induced lung injury. HXe-MR data were acquired in two healthy rats and one rat with radiation-induced lung injury using whole-lung spectroscopy and CSI-CSSR techniques. The CSI-CSSR acquisitions were performed with both fixed TE and variable TE. Apparent alveolar septal wall thickness, gas transfer dynamics, and regional lung function were quantified and compared across acquisition methods. Spectral analysis included alignment of dissolved-phase frequency spectra using the membrane resonance as reference, segmentation of gas-phase (GP) frequency distribution, and characterization of gas uptake in the vasculature. Complex GP line shapes were observed in rat lungs, necessitating pixel-wise CSI analysis and membrane resonance alignment for improved quantification. Notable differences in alveolar septal wall thickness, dissolved-phase GP ratios, and GP and red blood cell frequencies were found between acquisition techniques and lung conditions. CSI-CSSR provided unique insights into regional lung function, including the identification of distinct GP frequency zones potentially corresponding to different airway structures, and the ability to map relative xenon gas transport. Metrics from fixed-TE and variable-TE acquisitions usually differed by less than 10%, but the latter yielded a 20% SNR gain. HXe-MRS and CSI-CSSR techniques provide similar but not universally interchangeable insights into lung function, particularly in the presence of pathology.

Comparative effects of ranolazine and trimetazidine on cardiac structure and exercise capacity in a healthy rat model: a new doping agent?

Abstract Background/Introduction Anti-anginal drugs that have been shown to improve myocardial energy use include ranolazine and trimetazidine [1]. An inquiry is warranted into their ability to impact cardiac functions and exercise capacity. Purpose This study aims to evaluate the effects of ranolazine; and trimetazidine as a positive control group on cardiac structure and exercise capacity in a rodent model in comparison with the control group. Methods In a randomized, controlled trial, 24 Sprague-Dawley rats were divided into three groups: control, ranolazine, and trimetazidine. Rats were given daily doses of ranolazine (50 mg/kg/1 ml) [2], trimetazidine (10 mg/kg/1 ml) [3], or saline (control) via gastric gavage for 30 days. At the beginning of the trial, as well as on the 15th and 30th days, the rats were weighed, placed on rotarod, and assessed using transthoracic echocardiography (Figure 1). The rats underwent 21 days of forced swimming testing. According to the guidelines for rat exercise testing [4], signs of exhaustion, lack of coordinated movements, and failure to surface for three seconds following submersion in the water were designated as grounds for terminating the test. Weight, rotarod durations, M-mode and Doppler measurements, and forced swimming test durations were recorded on the 0th, 15th, and 30th days. Results No discernible differences were found between the groups in the initial evaluations. By using echocardiography, the left ventricular masses expanded in all three, indicating the emergence of an athlete's heart. In comparison to the control group, the ranolazine and trimetazidine groups showed considerable increases in their ability to exercise. In particular, the swimming times of the trimetazidine group and the ranolazine group improved to a mean of 1889 seconds by the 21st session, 1700 seconds in the trimetazidine group, and 1548 seconds in the control group (Figure 2), respectively, indicating enhanced cardiac performance. Conclusion(s) Ranolazine exhibits significant potential to enhance exercise capacity and cardiac efficiency in rats, surpassing the effects observed with trimetazidine. Trimetazidine is already registered as a doping agent in WADA [5]. These findings highlight the potential use of ranolazine as a performance enhancing agent in healthy subjects for a malicious purpose of creating unfair advantages in professional sports. Further studies in human subjects are needed.Figure 1Figure 2

The Possible Therapeutic Role of MSC Derived Exosomes Extracted from Myocardial Infarction versus Healthy Rat Models in the Heart with Surgically Occluded Right Anterior Coronary Artery in Rats A Histological Study

Abstract Introduction Myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary arteries of the heart, causing damage to the heart Muscle. The most common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck or jaw. Often it occurs in the center or left side of the chest and lasts for more than a few minutes. MI may cause heart failure, an irregular heartbeat, cardiogenic Shock or cardiac arrest. Aim: this study is designed to compare between the therapeutic role of autologous exosomes versus homologous exosomes on surgically induced myocardial infarction model in adult male albino rats. Material and Methods Fifty adult male albino rats weighing 150–250 gm were included with age from 8 to 11 old months in the study. In addition, ten rats weighing 150 gm with age from 7 to 8 old weeks were used for adipose derived exosomes preparation. The rats were divided into the following three groups: Group I: control group, Group II: myocardial infarction group; rats were subjected to right (RACO Technique), Group III: rats were subjected to permanent RACO technique as in group II then rats were further subdivided into two subgroups; Subgroup IIIa received autologous exosomes in tail vein on the 2nd day of the experiment and Subgroup IIIb received homologous exosomes in tail vein on the 2nd day of the experiment. Results Group II showed disruption of cardiomyoctes which appeared deeply acidophilic and darkly stained nuclei with loss of the intercalated discs and muscle striations. Immunohistochemical stain revealed a significantly increased reaction to iNOS antibodies, caspase-3 antibodies, anti -PCNA and positive anti-VEGF in comparison to control group. Group III; including subgroups IIIa and IIIb; showed preservation of the myocardium integrity. However, subgroup IIIa revealed significant increase in anti-VEGF and decrease in iNOS antibodies as compared to subgroup IIIb. Conclusion Both exosomes from healthy rats and exosomes from rats with MI showed therapeutic and anti-inflammatory effects in surgically induced MI. These effects were more prominent in exosomes from rats with MI than healthy rats as detected by microscopic, morphometric, and statistical studies.

BMSCs-derived exosomes carrying miR-668-3p promote progression of osteoblasts in osteonecrosis of the femoral head: Expression of proteins CD63 and CD9

Recently, exosomes that are derived from bone marrow mesenchymal stem cells (BMSCs) have garnered considerable interest due to their significant roles in the processes of bone regeneration and repair. Among the various molecular components present within these exosomes, miR-668-3p has emerged as a pivotal microRNA that may be instrumental in modulating the function and proliferation of osteoblasts, the cells responsible for bone formation. The primary objective of this research was to examine the enhancing effects of BMSC-derived exosomes that are enriched with miR-668-3p on the advancement of osteoblasts in the context of osteonecrosis of the femoral head. Furthermore, the study aimed to analyze how the expression of specific exosomal proteins, namely CD63 and CD9, influences this biological process. To conduct the investigation, BMSCs were isolated from healthy rat models, followed by the extraction of their secreted exosomes. The subsequent phase of the study involved assessing the proliferation and differentiation of osteoblasts by introducing the exosomes enriched with miR-668-3p into an experimental setup representing osteonecrosis of the femoral head. The findings revealed that exosomes derived from BMSCs, which contained miR-668-3p, significantly enhanced the proliferation of osteoblasts as well as the expression of key osteogenic marker genes. Notably, the levels of CD63 and CD9 proteins were markedly increased in the treated groups, indicating that the mechanisms underlying this promotion might involve cell adhesion and the endocytic uptake of exosomes.

Transamniotic Delivery of Surfactant Protein B mRNA in a Healthy Model

Introduction: We sought to determine whether exogenous surfactant protein B (SPB) mRNA could be incorporated and translated by the fetal lung after simple transamniotic administration. Methods: Fetuses (n = 149) of twelve time-dated dams underwent intra-amniotic injections of either human SPB (hSPB) mRNA encapsulated into lipopolyplex (mRNA, n = 99) or lipopolyplex without mRNA (control; n = 50) on gestational day 17 (E17, term = E21–22). Lungs were screened for hSPB by enzyme-linked immunosorbent assay daily until term. Phosphatidylcholine (PC) (a surrogate for surfactant production) was measured in the amniotic fluid by fluorometric assay. Statistical analysis included nonparametric Wilcoxon rank sum test. Results: Significantly improved survival in the mRNA group compared to controls was observed at E18 (100% vs. 85.7%) and E20 (100% vs. 83.3%) (both p < 0.001). When controlled by mRNA-free injections, hSPB protein was detected in the mRNA group’s lungs at E18, 19, and term (p = 0.002 to <0.001). Amniotic fluid PC levels were increased compared to control at term [285.9 (251.1, 363.9) μM versus 263.1 (222.8, 309.1) μM]; however, this did not reach significance (p = 0.33). Conclusions: Encapsulated exogenous SPB mRNA can be incorporated and translated by fetal lung cells following intra-amniotic injection in a healthy rat model. Transamniotic mRNA delivery could become a novel strategy for perinatal surfactant protein replacement.

Photoacoustic imaging for non-invasive assessment of biomarkers of intestinal injury in experimental necrotizing enterocolitis.

Necrotizing enterocolitis (NEC) is an often-lethal disease of the premature infant intestinal tract, exacerbated by significant diagnostic difficulties. In NEC, the intestine exhibits hypoperfusion and dysmotility, contributing to disease pathogenesis. However, these features cannot be accurately and quantitively assessed with current imaging modalities. We have previously demonstrated the ability of photoacoustic imaging (PAI) to non-invasively assess intestinal tissue oxygenation and motility in a healthy neonatal rat model. In this first-in-disease application, we evaluated NEC using PAI to assess intestinal health biomarkers in an experimental model of NEC. NEC was induced in neonatal rats from birth to 4-days. Healthy breastfed (BF) and NEC rat pups were imaged at 2- and 4-days. Intestinal tissue oxygen saturation was measured with PAI, and NEC pups showed significant decreases at 2- and 4-days. Ultrasound and PAI cine recordings were used to capture intestinal peristalsis and contrast agent transit within the intestine. Intestinal motility, assessed using computational intestinal deformation analysis, demonstrated significant reductions in both early and established NEC. NEC damage was confirmed with histology and dysmotility was confirmed by small intestinal transit assay. This preclinical study presents PAI as an emerging diagnostic imaging modality for intestinal disease assessment in premature infants. Necrotizing enterocolitis (NEC) is a devastating intestinal disease affecting premature infants with significant mortality. NEC presents significant clinical diagnostic difficulties, with limited diagnostic confidence complicating timely and effective interventional efforts. This study is an important foundational first-in-disease preclinical study that establishes the utility for PAI to detect changes in intestinal tissue oxygenation and intestinal motility with NEC disease induction and progression. This study demonstrates the feasibility and exceptional promise for the use of PAI to non-invasively assess oxygenation and motility in the healthy and diseased infant intestine.

Impact of resistant starch: Absorption of dietary minerals, glycemic index and oxidative stress in healthy rats

Background & AimsResistant starch (RS) is a prebiotic fiber that has been scientifically shown to control the development of obesity. Prebiotic role of RS has also seen to be very important as it helps gut bacteria to regulate fermentation and fatty acid production. This study aimed to check the different levels of RS on glycemic index, oxidative stress and mineral absorption rate in healthy rat models. To evaluate these objectives, the trial was conducted for 40 days of follow up; 10 days were the adjustment period and the collection period over 30 days. MethodsThirty-six healthy female Wistar rats were divided into 4 groups of (9 animals each) NC (Normal Control: without resistant starch), RS0.20 (resistant starch: 0.20 g/kg body weight), RS0.30 (resistant starch: 0.30g/kg body weight), RS0.40 (resistant starch: 0.40g/kg body weight). All the diets were isocaloric and isonitroginous. ResultsThe impact of different levels of RS on the dry-matter intake (DMI) presented statistically significant results (p ≤ .05): DMI was reduced in RS (0.02) fed rats as compared to NC rats in first 3 weeks; and after 4th and 5th weeks, there was a DMI reduction of 28% in RS (0.04) fed rats. Moreover, there was no significant increase in the nutrient intake in all RS diets. The dry-matter (DM) digestibility was statistically significantly (P≤0·05), which increased in all rats fed with different level of RS. The weight loss showed statistically significant results: RS (0.04) exhibited 19g reduction in weight as compared with NC rats. Significant increase was observed in total oxidant status (TOS), in all the RS fed rats when compared with NC rats. The levels of Mg, Ca, Fe and Zn were shown to be decrease in feces analysis, which proves their better absorbance in gut. Statistically significant increase was observed in antioxidant capacity, whereas significant decrease was observed in the total weight of the animals, showing the role of RS in controlling obesity. ConclusionsOverall, significant results were found in all dosage level of RS but long term administration of the higher dosage level (RS0.40) may need to be studied for enhanced results. RS can help improve insulin sensitivity in overweight adults.

Polyester Nanoparticles with Controlled Topography for Peroral Drug Delivery Using Insulin as a Model Protein.

Receptor-mediated polyester drug delivery systems have tremendous potential for improving the clinical performance of existing pharmaceutical drugs. Despite significant progress made in this area, it remains unclear how and to what extent the polyester nanoparticle surface topography would affect the in vitro, ex vivo and in vivo performance of a drug, and if there exists a correlation between in vitro and in vivo, as well as healthy versus pathophysiological states. Herein, we report a systematic investigation of the interactions between ligands and receptors as a function of the linker length, two-carbon (2C) versus four-carbon (4C). The in vitro, ex vivo and in vivo in healthy models validate the hypothesis that 4C has better reach and binding to the receptors. The results indicate that 4C offered better performance over 2C in vivo in improving the oral bioavailability of insulin (INS) by 1.1-fold (3.5-fold compared to unfunctionalized nanoparticles) in a healthy rat model. Similar observations were made in pathophysiological models; however, the effects were less prominent compared to those in healthy models. Throughout, ligand decorated nanoparticles outperformed unfunctionalized nanoparticles. Finally, a semimechanistic pharmacokinetic and pharmacodynamic (PKPD) model was developed using the experimental data sets to quantitatively evaluate the effect of P2Ns-GA on oral bioavailability and efficacy of insulin. The study presents a sophisticated oral delivery system for INS or hydrophilic therapeutic cargo, highlighting the significant impact on bioavailability that minor adjustments to the surface chemistry can have.

Comparative Effect of Amylose Concentration in Brown and White Rice on Hepatocellular Insufficiency Using Rat Bioassay

Background: The scientific name of rice is Oryza sativa. It is one of the important staple human foods. There are more than 110,000 cultivated varieties of rice, most widely known and grown. Nutrient concentration may vary depending on production, environment, pre- and post-harvesting treatment, and processing. Cooked rice with high amylose content effectively controls metabolic disorders, serum blood glucose levels, and lipid profile and is also effective in weight loss. Objectives: This study aimed to determine the comparative effect of amylose concentration in brown and white rice on hepatocellular insufficiency in healthy rat models. Methods: We divided 25 rats into 5 groups (G0, G1, G2, G3, and G4). There were 5 rats in each group. Group 0 was the control group on a normal diet. Group 1 was fed white rice flour, G2 was fed cooked white rice, G3 was fed brown rice flour, and G4 was fed cooked brown rice. Free access to food and water was secured. Weight changes, blood glucose, and lipid profiles were analyzed pre and post-treatment. Results: Rats on white rice feed showed weight gain, increased blood glucose, cholesterol, triglycerides, and low HDL levels. However, rats on brown rice feed showed less weight gain (P &lt; 0.05), a lower increase in blood glucose (P &lt; 0.05), high HDL, lower LDL cholesterol, and triglycerides. The pancreas and liver histopathology showed no major changes due to the short trial duration. Conclusions: Rats fed white rice showed ineffective results disturbing biological parameters as compared to those rats which were fed brown rice. Due to low amylose content and the presence of antioxidants, flavonoids, and high fiber content, brown rice shows beneficial effects in controlling and maintaining relevant biological parameters.

Bidirectional Feto-Maternal Traffic of Donor Mesenchymal Stem Cells Following Transamniotic Stem Cell Therapy (TRASCET)

PurposeTransamniotic stem cell therapy (TRASCET) with mesenchymal stem cells (MSCs) has emerged experimentally as a potential treatment for different congenital diseases and maternal diseases of pregnancy. The broad applicability of TRASCET is predicated on hematogenous routing of donor MSCs via the placenta. We investigated whether donor MSC kinetics includes bidirectional traffic between the fetus and mother. MethodsEight time-dated dams had their fetuses (n = 96) divided in 4 groups on gestational day 17 (E17, term = E21). Groups populating one uterine horn received intra-amniotic injections (50 μL) of either donor amniotic fluid-derived MSCs (2×106 cells/mL) labelled with a firefly luciferase reporter gene (MSC-injected, n = 32), or of acellular luciferase (luciferase-injected, n = 26). Contra-lateral (CL) horn fetuses received no injection (MSC-CL, n = 20 and luciferase-CL, n = 18). At term, samples from 11 fetal anatomical sites from CL fetuses, along with placentas from all fetuses and maternal blood were screened for luciferase activity via microplate luminometry. ResultsOverall survival was 95 % (91/96). When controlled by the acellular injection, positive luciferase activity was observed in the placentas of all MSC-injected fetuses, confirming viability of the donor cells at term. When controlled by the acellular injection group, MSC-CL fetuses showed positive luciferase activity in the bone marrow, peripheral blood, brain and skin (p = <0.001–0.048). No luciferase activity was detected in any maternal blood sample. ConclusionAmniotic fluid-derived MSCs can traffic between the fetus and mother in both directions after simple intra-amniotic injection, in a healthy rat model. This phenomenon must be considered in TRASCET performed in twin/multiple pregnancies. Level of evidenceN/A (animal and laboratory study).

The Dynamics of Nerve Degeneration and Regeneration in a Healthy Milieu and in Diabetes.

Appropriate animal models, mimicking conditions of both health and disease, are needed to understand not only the biology and the physiology of neurons and other cells under normal conditions but also under stress conditions, like nerve injuries and neuropathy. In such conditions, understanding how genes and different factors are activated through the well-orchestrated programs in neurons and other related cells is crucial. Knowledge about key players associated with nerve regeneration intended for axonal outgrowth, migration of Schwann cells with respect to suitable substrates, invasion of macrophages, appropriate conditioning of extracellular matrix, activation of fibroblasts, formation of endothelial cells and blood vessels, and activation of other players in healthy and diabetic conditions is relevant. Appropriate physical and chemical attractions and repulsions are needed for an optimal and directed regeneration and are investigated in various nerve injury and repair/reconstruction models using healthy and diabetic rat models with relevant blood glucose levels. Understanding dynamic processes constantly occurring in neuropathies, like diabetic neuropathy, with concomitant degeneration and regeneration, requires advanced technology and bioinformatics for an integrated view of the behavior of different cell types based on genomics, transcriptomics, proteomics, and imaging at different visualization levels. Single-cell-transcriptional profile analysis of different cells may reveal any heterogeneity among key players in peripheral nerves in health and disease.

833-P: Duodenal Targeting by Oral Pharmacologic Duodenal Exclusion Therapy for Treatment of Type 2 Diabetes (T2D)

GLY-200 is an oral, non-absorbed polymeric drug designed to non-invasively and reversibly enhance the mucus lining of the proximal small intestine to mimic the effects of metabolic surgery and duodenal exclusion devices. In healthy volunteers and rat models of T2D (GK, ZDF, and DIO), GLY-200 produced reductions in postprandial glucose and bodyweight compared to control. This study aimed to visualize the retained duodenal barrier in rats using appropriate imaging modalities. Methods: Imaging of GLY-200 after gavage administration to fasted Sprague-Dawley rats was performed using Computed Tomography (CT) and an In Vivo Imaging System (IVIS). For CT imaging, GLY-200 was covalently conjugated with diatrizoate; images were obtained after transient isoflurane administration 1, 2, and 4 hours after gavage. For IVIS imaging, GLY-200 was reacted with FITC to produce a fluorescein-GLY-200 conjugate. Rats were euthanized 0.5, 1, 2, 4, and 8 hours after dosing and the GI tracts were immediately removed for imaging. Results: In CT imaging, GLY-200-diatrizoate was retained in the proximal small intestine 1 and 2 hours after administration, with an intense signal only in the duodenum. In comparison, a diatrizoate control was broadly distributed over the small intestine distal to the duodenum by 1 hour. In IVIS imaging, GLY-200-FITC showed intense fluorescence in the proximal small intestine that was predominantly associated with the gut wall and persisted for &amp;gt;4 hours after administration. In comparison, a FITC-dextran70 control was distributed broadly throughout the distal intestine and cecum by 30 minutes with no retention in the duodenum. Conclusion: Imaging studies confirm that GLY-200 conjugates are retained in the duodenum after oral administration. These data support the hypothesis that GLY-200 treatment results in a pharmacologic duodenal exclusion that could potentially recapitulate the glycemic and weight effects of metabolic surgery and duodenal exclusion devices. Disclosure A.Nimgaonkar: Employee; Glyscend Inc. C.Bryant: Employee; Glyscend Inc. T.Carlson: Employee; Glyscend Inc. F.V.Guerina: Employee; Glyscend Inc. K.Colbert: Consultant; LifeSprout, Employee; Glyscend Inc. S.Polomoscanik: None. J.S.Petersen: None. T.H.Jozefiak: Employee; Glyscend Inc., Stock/Shareholder; Glycologix, LLC. M.Fineman: Employee; Glyscend Inc., Stock/Shareholder; Glyscend Inc.

Investigation of Age-Related Alterations in Brain and Serum Samples in a Healthy Aging Rat Model

Male albino rats of Wistar strain (n=24) were assigned to three groups 2-month old (GRP I), 9-month old (GRP II) and 15-month old (GRP III) ,(n=8 in each ) in order to investigate age related changes in serum and brain samples. Malondialdehyde (MDA), reduced glutathione (GSH), acetylcholinesterase (AChE) and paraoxanase (PON) enzyme activites , soluble and aggregated amyloid β1-42 (Aβ1-42) levels were analyzed in brain tissues. Tissues were also stained with Congo-red dye in order to observe fibrillation. Serum total cholesterol, uric acid and triglyceride levels and PON activites were investigated. Serum uric acid levels were significantly decreased (p

Amplification of Wound Healing by Propolis and Honey Ointment in Healthy and Diabetic Rat Models; Histopathological and Morphometric Findings.

Skin wound healing, especially in diabetic patients, has been a major medical challenge for decades. In the meantime, the use of traditional medicine has always been questioned. Propolis) resin and wax (is one of the most likely solutions to this problem. The present study aimed to establish an animal model for healing skin wounds and diabetic ulcers. To this aim, rats were randomly allocated into two healthy and diabetic groups (50 mg/kg streptozotocin resulted in diabetes with high BSL to 300 mg/dL), which were divided into four subgroups. The 7 mm full-thickness skin wounds were created on the abdomen region in 80 male Wistar rats using paunch. In the subgroups, the wounds were cleaned with normal 0.9% saline as the control subgroup and dressed with Eucerit, 1.5% honey+eucerit, and 3% propolis +1.5% honey+eucerit, once daily for 14 days in other subgroups, respectively. On days 1, 3, 5, and 7 after the intervention, wound and area contractions were calculated using digital photographs measurement. The histopathological and semi-quantitative studies were performed on days 7 and 14 after wounds creation. The microscopic findings demonstrated that the granulation tissue, fibroblasts, re-epithelization, and angiogenesis increased (P≤0.05) in the subgroups treated by propolis and honey combination in healthy and diabetic rats within 7 and 14 days post-injury. Also, less inflammation and a significant reduction in wound contraction were observed in the same subgroups on days 3, 5, and 7 compared to other subgroups (P≤0.05). The results indicated that significant healing quality and acceleration were affected by propolis and honey compared to other subgroups on days 3 and 5 (P≤0.05).

Brain Gene Silencing with Cationic Amino-Capped Poly(ethylene glycol) Polyplexes.

Therapeutic gene silencing in the brain is usually achieved using highly invasive intracranial administration methods and/or comparatively toxic vectors. In this work, we use a relatively biocompatible vector: poly(ethylene glycol) star-shaped polymer capped with amine groups (4APPA) via the nose to brain route. 4APPA complexes anti- itchy E3 ubiquitin protein ligase (anti-ITCH) siRNA to form positively charged (zeta potential +15 ± 5 mV) 150 nm nanoparticles. The siRNA-4APPA polyplexes demonstrated low cellular toxicity (IC50 = 13.92 ± 6 mg mL−1) in the A431 cell line and were three orders of magnitude less toxic than Lipofectamine 2000 (IC50 = 0.033 ± 0.04 mg mL−1) in this cell line. Cell association and uptake of fluorescently labelled siRNA bound to siRNA-4APPA nanoparticles was demonstrated using fluorescent activated cell sorting (FACS) and confocal laser scanning microscopy (CLSM), respectively. Gene silencing of the ITCH gene was observed in vitro in the A431 cell line (65% down regulation when compared to the use of anti-ITCH siRNA alone). On intranasal dosing with fluorescently labelled siRNA-4APPA polyplexes, fluorescence was seen in the cells of the olfactory bulb, cerebral cortex and mid-brain regions. Finally, down regulation of ITCH was seen in the brain cells (54 ± 13% ITCH remaining compared to untreated controls) in a healthy rat model, following intranasal dosing of siRNA-4APPA nanoparticles (0.15 mg kg−1 siRNA twice daily for 3 days). Gene silencing in the brain may be achieved by intranasal administration of siRNA- poly(ethylene glycol) based polyplexes.

Polyphosphate-crosslinked collagen scaffolds for hemostasis and alveolar bone regeneration after tooth extraction.

Post-extraction bleeding and alveolar bone resorption are the two frequently encountered complications after tooth extraction that result in poor healing and rehabilitation difficulties. The present study covalently bonded polyphosphate onto a collagen scaffold (P-CS) by crosslinking. The P-CS demonstrated improved hemostatic property in a healthy rat model and an anticoagulant-treated rat model. This improvement is attributed to the increase in hydrophilicity, increased thrombin generation, platelet activation and stimulation of the intrinsic coagulation pathway. In addition, the P-CS promoted the in-situ bone regeneration and alveolar ridge preservation in a rat alveolar bone defect model. The promotion is attributed to enhanced osteogenic differentiation of bone marrow stromal cells. Osteogenesis was improved by both polyphosphate and blood clots. Taken together, P-CS possesses favorable hemostasis and alveolar ridge preservation capability. It may be used as an effective treatment option for post-extraction bleeding and alveolar bone loss.Statement of significanceCollagen scaffold is commonly used for the treatment of post-extraction bleeding and alveolar bone loss after tooth extraction. However, its application is hampered by insufficient hemostatic and osteoinductive property. Crosslinking polyphosphate with collagen produces a modified collagen scaffold that possesses improved hemostatic performance and augmented bone regeneration potential.

Assessment of hepatic function, perfusion and parenchyma attenuation with indocyanine green, ultrasound and computed tomography in a healthy rat model: Preliminary determination of baseline parameters in a healthy liver.

Defining reference intervals in experimental animal models plays a crucial role in pre-clinical studies. The hepatic parameters in healthy animals provide useful information about type and extension of hepatic damage. However, in the majority of the cases, to obtain them require an invasive techniques. Our study combines these determinations with dynamic functional test and imaging techniques to implement a non-invasive protocol for liver evaluation. The aim of the study was to determine reference intervals for hepatic function, perfusion and parenchyma attenuation with analytical and biochemical blood parameters, indocyanine green, ultrasound and computed tomography in six healthy SD rats. Six males healthy SD rats were followed for 4 weeks. To determine hepatic function, perfusion and parenchyma attenuation analytical and biochemical blood parameters, indocyanine green, ultrasound and computed tomography were studied. Results were expressed as Means ± standard error of mean (SEM). The significance of differences was calculated by using student t-test, p < 0.05 was considered statistically significant. Indocyanine green clearance 5 and 10 minutes after its injection was 80.12% and 96.59%, respectively. Approximate rate of decay during the first 5 minutes after injection was 38% per minute. Hepatic perfusion evaluation with the high-frequency ultrasound was related to cardiovascular hemodynamic and renal perfusion. Portal area, hepatic artery resistance index, hepatic artery and portal peak systolic velocity and average between hepatic artery and porta was 3.41 ± 0.62 mm2, 0.57 ± 0.04 mm2/s, 693.24±102.53 mm2/s, 150.72 ± 17.80 mm2/s and 4.82 ± 0.96 mm2/s, respectively. Heart rate, cardiac output, left renal artery diammetre and renal blood flow were 331.01 ± 22.22 bpm, 75.58 ± 8.72 mL/min, 0.88 ± 0.04 mm2 and 13.65 ± 1.95 mm2/s. CT-scan hepatic average volume for each rat were 21.08±3.32, 17.57±2.76, 14.87±2.83 and 13.67±2.45 cm3 with an average attenuation coefficient of 113.51±18.08, 129,19±7.18, 141,47±1.95 y 151,67±1.2 HU. Indocyanine green and high-frequency ultrasound could be used in rats as a suitable marker of liver function. Computed tomography, through the study of raw data, help to characterize liver parenchyma, and could be a potential tool for early detection of liver parenchymal alterations and linear follow-up of patients. Further studies in rats with liver disease are necessary to verify the usefulness of these parameters.

Partial Substitution of Meat with Insect (Alphitobius diaperinus) in a Carnivore Diet Changes the Gut Microbiome and Metabolome of Healthy Rats.

Insects are suggested as a sustainable protein source of high nutritional quality, but the effects of insect ingestion on processes in the gastrointestinal tract and gut microbiota (GM) remain to be established. We examined the effects of partial substitution of meat with insect protein (Alphitobius diaperinus) in a four-week dietary intervention in a healthy rat model (n = 30). GM composition was characterized using’ 16S rRNA gene amplicon profiling while the metabolomes of stomach, small intestine, and colon content, feces and blood were investigated by 1H-NMR spectroscopy. Metabolomics analyses revealed a larger escape of protein residues into the colon and a different microbial metabolization pattern of aromatic amino acids when partly substituting pork with insect. Both for rats fed a pork diet and rats fed a diet with partial replacement of pork with insect, the GM was dominated by Lactobacillus, Clostridium cluster XI and Akkermansia. However, Bray-Curtis dissimilarity metrics were different when insects were included in the diet. Introduction of insects in a common Western omnivore diet alters the gut microbiome diversity with consequences for endogenous metabolism. This finding highlights the importance of assessing gastrointestinal tract effects when evaluating new protein sources as meat replacements.

A nanoemulsion/micelles mixed nanosystem for the oral administration of hydrophobically modified insulin

The potential of nanoemulsions for the oral administration of peptides is still in its early stage. The aim of the present work was to rationally design, develop, and fully characterize a new nanoemulsion (NE) intended for the oral administration of hydrophobically modified insulin (HM-insulin). Specific components of the NE were selected based on their enhancing permeation properties as well as their ability to improve insulin association efficiency (Miglyol 812, sodium taurocholate), stability in the intestinal fluids, and mucodiffusion (PEGylated phospholipids and poloxamer 407). The results showed that the NE co-existed with a population of micelles, forming a mixed system that exhibited a 100% of HM-insulin association efficiency. The nanosystem showed good stability and miscibility in different bio-relevant media and displayed an acceptable mucodiffusive behavior in porcine mucus. In addition, it exhibited a high interaction with cell mono-cultures (Caco -2 and C2BBe1 human colon carcinoma Caco-2 clone cells) and co-cultures (C2BBe1 human colon carcinoma Caco-2 clone/HT29-MTX cells). The internalization in Caco-2 monolayers was also confirmed by confocal microscopy. Finally, the promising in vitro behavior of the nanosystem in terms of overcoming the biological barriers of the intestinal tract was translated into a moderate, although significant, hypoglycemic response (≈ 20–30%), following intestinal administration to both healthy and diabetic rat models. Overall, this information underlines the crucial steps to address when designing peptide-based nanoformulations to successfully overcome the intestinal barriers associated to the oral modality of administration.Graphical abstract