Enalapril Diminishes the Diabetes-Induced Changes in Intestinal Morphology, Intestinal RAS and Blood SCFA Concentration in Rats.

Evidence suggests that microbiota-derived metabolites, including short-chain fatty acids (SCFAs) and trimethylamine-oxide (TMAO), affect the course of diabetic multiorgan pathology. We hypothesized that diabetes activates the intestinal renin-angiotensin system (RAS), contributing to gut pathology. Twelve-week-old male rats were divided into three groups: controls, diabetic (streptozotocin-induced) and diabetic treated with enalapril. Histological examination and RT-qPCR were performed to evaluate morphology and RAS expression in the jejunum and the colon. SCFA and TMAO concentrations in stools, portal and systemic blood were evaluated. In comparison to the controls, the diabetic rats showed hyperplastic changes in jejunal and colonic mucosa, increased plasma SCFA, and slightly increased plasma TMAO. The size of the changes was smaller in enalapril-treated rats. Diabetic rats had a lower expression of Mas receptor (MasR) and angiotensinogen in the jejunum whereas, in the colon, the expression of MasR and renin was greater in diabetic rats. Enalapril-treated rats had a lower expression of MasR in the colon. The expression of AT1a, AT1b, and AT2 receptors was similar between groups. In conclusion, diabetes produces morphological changes in the intestines, increases plasma SCFA, and alters the expression of renin and MasR. These alterations were reduced in enalapril-treated rats. Future studies need to evaluate the clinical significance of intestinal pathology in diabetes.

Keratin Scaffolds Containing Casomorphin Stimulate Macrophage Infiltration and Accelerate Full-Thickness Cutaneous Wound Healing in Diabetic Mice.

Impaired wound healing is a major medical challenge, especially in diabetics. Over the centuries, the main goal of tissue engineering and regenerative medicine has been to invent biomaterials that accelerate the wound healing process. In this context, keratin-derived biomaterial is a promising candidate due to its biocompatibility and biodegradability. In this study, we evaluated an insoluble fraction of keratin containing casomorphin as a wound dressing in a full-thickness surgical skin wound model in mice (n = 20) with iatrogenically induced diabetes. Casomorphin, an opioid peptide with analgesic properties, was incorporated into keratin and shown to be slowly released from the dressing. An in vitro study showed that keratin-casomorphin dressing is biocompatible, non-toxic, and supports cell growth. In vivo experiments demonstrated that keratin-casomorphin dressing significantly (p < 0.05) accelerates the whole process of skin wound healing to the its final stage. Wounds covered with keratin-casomorphin dressing underwent reepithelization faster, ending up with a thicker epidermis than control wounds, as confirmed by histopathological and immunohistochemical examinations. This investigated dressing stimulated macrophages infiltration, which favors tissue remodeling and regeneration, unlike in the control wounds in which neutrophils predominated. Additionally, in dressed wounds, the number of microhemorrhages was significantly decreased (p < 0.05) as compared with control wounds. The dressing was naturally incorporated into regenerating tissue during the wound healing process. Applied keratin dressing favored reconstruction of more regular skin structure and assured better cosmetic outcome in terms of scar formation and appearance. Our results have shown that insoluble keratin wound dressing containing casomorphin supports skin wound healing in diabetic mice.

Comparison of GC-MS and MEKC methods for caffeine determination in preworkout supplements.

In this study, GC-MS- and MEKC-based methods for determination of caffeine (CAF) in preworkout supplements were developed and validated. The proposed protocols utilized minimal sample preparation (simple dilution and syringe filtration). The developed methods achieved satisfactory validation parameters, i.e. good linearity (R2 > 0.9988 and R2 > 0.9985 for GC-MS- and MEKC-based method, respectively), satisfactory intra- and interaccuracy (within 92.6-100.7% for method utilizing GC-MS and 92.1-110.3% for protocol based on MEKC) and precision (CV < 15.9% and CV < 6.3% for GC-MS- and MEKC-based method, respectively) and recovery (within 100.1-100.8% for method utilizing GC-MS and 101.5-106.2% for protocol based on MEKC). The LOD was 0.03 and 3 µg/mL for method utilizing GC-MS and MEKC, respectively. The CAF concentrations determined by GC-MS- and MEKC-based methods were found to be in the range of 8.53-11.23 and 8.20-11.61 µg/mL, respectively. Taking into consideration information on the labels, the investigated supplements were found to contain from 110.0 to 167.3% of the declared CAF content, which confirmed the literature reports on incompatibility of the declared product compositions with real ones. Nevertheless, the consumption of examined supplements as recommended by producers did not lead to exceeding the CAF safe limit of 400 mg per day. Additionally, the MEKC-based method allowed for detection and identification of vitamin B3 and B6 in all of the investigated supplement samples, which demonstrated that MEKC-based protocols may be an appropriate assays for simultaneous determination of CAF and vitamins.

Application of micellar electrokinetic chromatography for detection of silver nanoparticles released from wound dressing.

The recent emergence of nanotechnology has provided a new therapeutic modality in case of silver nanoparticles. Dressings containing silver form the basis for the treatment of burns and wounds, either acute or chronic ones. The aim of the study was to examine silver release from the different wound dressings: commercially available (Atrauman Ag, Aquacel Ag) and experimental (FKDP-AgNPs) using MEKC. In order to characterize prepared keratin based wound dressing before and after its modification with AgNPs, a compositional analysis was conducted using energy dispersive X-ray spectroscopy. Nanosilver toxicity was evaluated with the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4 sulfophenyl)-2H-tetrazolium test. Silver release from wound dressings was assessed using MEKC. The best separation was observed for MEKC in 20 mM borate buffer at pH 9 with 20 mM SDS addition. In vitro studies showed silver at higher concentration than 10 ppm exerted a toxic effect on fibroblasts isolated from diabetic mice versus. NIH/3T3 and BJ cell lines (p < 0.05). We observed silver was released more gradually from experimental FKDP-AgNPs wound dressing, in compare to commercially available wound dressings. The fast and low-cost method utilizing MEKC can be used in clinical practice to detect silver release from the wound dressings.

Inflammatory bowel disease is associated with increased gut-to-blood penetration of short-chain fatty acids: A new, non-invasive marker of a functional intestinal lesion.

NEW FINDINGS: What is the central question of this study? 'Leaky gut' has been found in intestinal and extra-intestinal diseases. However, functional evaluation of intestinal permeability is not widely used as a diagnostic marker, possibly owing to significant limitations of currently used permeability assays. There is an unmet need for development of a new, non-invasive test to assess intestinal function. What is the main finding and its importance? We show that an increased blood-to-stool ratio of the concentration of gut bacteria-produced short-chain fatty acids may be used as a marker of gut permeability. Our findings lay the groundwork for establishing a new, non-invasive, risk-free diagnostic tool in diseases associated with intestinal barrier malfunction, such as inflammatory bowel disease. ABSTRACT: Intestinal diseases, such as inflammatory bowel disease (IBD), are characterized by an impaired gut-blood barrier commonly referred to as 'leaky gut'. Therefore, functional evaluation of the gut-blood barrier is a promising diagnostic marker. We hypothesized that short-chain fatty acids (SCFAs) produced by gut bacteria might serve as a marker in IBD. Animal experiments were performed on male Sprague-Dawley rats with acetic acid-induced colitis and in sham control animals. The gut-blood barrier permeability was determined by assessing the ratios of the following: (i) portal blood concentration of SCFAs (Cp ) to faecal concentration of SCFAs (Cf ); (ii) systemic blood concentration of SCFAs (Cs ) to faecal concentration of SCFAs (Cf ); and (iii) Cp and Cs of fluorescein isothiocyanate (FITC)-dextran administered into the colon. As a clinical study, we evaluated Cs , Cf and the Cs /Cf ratio of SCFAs in six paediatric patients with IBD, assessed as mild/moderate/severe by the Paediatric Ulcerative Colitis Activity Index (PUCAI) and the Paediatric Crohn's Disease Activity Index (PCDAI) at the time of sample collection, and nine age-matched healthy control subjects. Rats with histologically confirmed IBD had significantly increased ratios of Cp /Cf and Cs /Cf for SCFAs. This was positively correlated with the plasma FITC-dextran concentration. Likewise, IBD patients showed a significantly higher Cs /Cf ratio for SCFAs, including acetic, valeric, isocaproic, caproic and propionic acids, in comparison to control subjects. In conclusion, in the rats and in paediatric patients with IBD we found an increased blood-to-stool ratio of SCFAs, suggesting an increased gut-to-blood penetration of SCFAs. These findings pave the way for a new, non-invasive diagnostic tool in IBD and other diseases accompanied by intestinal barrier malfunction.

Chronic, low-dose TMAO treatment reduces diastolic dysfunction and heart fibrosis in hypertensive rats.

Several studies have suggested negative effects of trimethylamine oxide (TMAO) on the circulatory system. However, a number of studies have shown protective functions of TMAO, a piezolyte and osmolyte, in animals exposed to high hydrostatic and/or osmotic stress. We evaluated the effects of TMAO treatment on the development of hypertension and its complications in male spontaneously hypertensive rats (SHRs) maintained on water (SHR-Water) and SHRs drinking TMAO water solution from weaning (SHR-TMAO). Wistar-Kyoto (WKY) rats were used as normotensive controls to discriminate between age-dependent and hypertension-dependent changes. Telemetry measurements of blood pressure were performed in rats between the 7th and 16th weeks of life. Anesthetized rats underwent echocardiographic, electrocardiographic, and direct left ventricular end-diastolic pressure (LVEDP) measurements. Hematoxylin and eosin as well as van Gieson staining for histopathological evaluation were performed. Plasma TMAO measured by chromatography coupled with mass spectrometry was significantly higher in the SHR-Water group compared with the WKY group (~20%). TMAO treatment increased plasma TMAO by four- to fivefold and did not affect the development of hypertension in SHRs. Sixteen-week-old rats in the SHR-Water and SHR-TMAO groups (12-wk TMAO treatment) showed similar blood pressures, angiopathy, and cardiac hypertrophy. However, the SHR-TMAO group had lower plasma NH2-terminal pro-B-type natriuretic peptide, LVEDP, and cardiac fibrosis. In contrast to age-matched WKY rats, 60-wk-old SHRs showed hypertensive angiopathy and heart failure with preserved ejection fraction. Compared with the SHR-Water group, the SHR-TMAO group (56-wk TMAO treatment) showed significantly lower plasma NH2-terminal pro-B-type natriuretic peptide and vasopressin, significantly lower LVEDP, and cardiac fibrosis. In conclusion, a four- to fivefold increase in plasma TMAO does not exert negative effects on the circulatory system. In contrast, increased dietary TMAO seems to reduce diastolic dysfunction in pressure-overloaded hearts in rats. NEW & NOTEWORTHY Chronic, low-dose trimethylamine oxide (TMAO) treatment that increases plasma TMAO by four- to fivefold reduces plasma NH2-terminal pro-B-type natriuretic peptide and vasopressin, left ventricular end-diastolic pressure, and cardiac fibrosis in pressure-overloaded hearts in hypertensive rats. Our study provides evidence that a moderate increase in plasma TMAO does not have a negative effect on the circulatory system. In contrast, increased dietary TMAO seems to reduce diastolic dysfunction in the pressure-overloaded heart.

Colonic indole, gut bacteria metabolite of tryptophan, increases portal blood pressure in rats.

Portal hypertension (PH) is a potentially life-threatening condition. We investigated the effects of indole and dietary tryptophan, a substrate for gut bacterial production of indole, on portal blood pressure (PBP), portal blood flow (PBF), and arterial blood pressure (ABP) in Sprague-Dawley rats (SD) and SD with PH induced by liver cirrhosis (SD-PH). Hemodynamics were recorded in anesthetized male 28-wk-old SD and SD-PH at baseline and after the administration of either a vehicle or indole into the colon. Blood levels of tryptophan and its bacterial metabolites were evaluated using chromatography coupled with mass spectrometry. Indole at lower doses increased PBP and PBF. Indole at higher doses produced a transient increase in PBP, which was accompanied by a decrease in ABP. Portal blood levels of indole, indole-3-propionic, indole-3-lactic, and indole-3-acetic acids were higher in SD-PH, suggesting an increased gut-blood barrier permeability. Rats on a tryptophan-rich diet showed a significantly higher PBP and portal blood level of indoles than rats on a tryptophan-free diet. In conclusion, a tryptophan-rich diet and intracolonic indole increase PBP and portal blood level of indole. Rats with PH show an increased penetration of indoles from the colon to the circulation. Intracolonic indole production may be of therapeutic importance in PH.

Enalapril decreases rat plasma concentration of TMAO, a gut bacteria-derived cardiovascular marker.

INTRODUCTION: Increased plasma level of trimethylamine N-oxide (TMAO), a bacterial metabolite of choline, is associated with an increased cardiovascular risk. Indoxyl sulfate, a bacterial metabolite of tryptophan, is thought to be associated with higher mortality in cardiorenal syndrome. We hypothesized that enalapril, a well-established drug reducing cardiovascular mortality, may affect the plasma level of gut bacteria-derived metabolites and gut bacteria composition. MATERIALS AND METHODS: 14-16-week-old Wistar rats were maintained either on water (controls) or water solution of enalapril for two weeks (5.3 or 12.6 mg/kg b.w.). Blood plasma and urine were analyzed for the concentration of TMAO and indoxyl sulfate using liquid chromatography coupled with triple-quadrupole mass spectrometry. Gut bacteria composition was analyzed with 16S rRNA gene sequence analysis. RESULTS: Rats treated with enalapril showed a significantly lower plasma TMAO level and a trend towards higher 24 h urine excretion of TMA and TMAO. Plasma indoxyl level was similar between the groups. There was no significant difference between the groups in gut bacteria composition. CONCLUSIONS: Enalapril decreases rat plasma TMAO, but does not affect the plasma level of indoxyl sulfate and gut bacteria composition. The enalapril-induced decrease in plasma TMAO level may be of therapeutic and diagnostic importance.

Salivary Hydrogen Sulfide Measured with a New Highly Sensitive Self-Immolative Coumarin-Based Fluorescent Probe.

Ample evidence suggests that H2S is an important biological mediator, produced by endogenous enzymes and microbiota. So far, several techniques including colorimetric methods, electrochemical analysis and sulfide precipitation have been developed for H2S detection. These methods provide sensitive detection, however, they are destructive for tissues and require tedious sequences of preparation steps for the analyzed samples. Here, we report synthesis of a new fluorescent probe for H2S detection, 4-methyl-2-oxo-2H-chromen-7-yl 5-azidopentanoate (1). The design of 1 is based on combination of two strategies for H2S detection, i.e., reduction of an azido group to an amine in the presence of H2S and intramolecular lactamization. Finally, we measured salivary H2S concentration in healthy, 18⁻40-year-old volunteers immediately after obtaining specimens. The newly developed self-immolative coumarin-based fluorescence probe (C15H15N3O4) showed high sensitivity to H2S detection in both sodium phosphate buffer at physiological pH and in saliva. Salivary H2S concentration in healthy volunteers was within a range of 1.641⁻7.124 µM.

Scalp involvement in pemphigus: a prognostic marker.

INTRODUCTION: Scalp involvement in the course of pemphigus is observed in 16-60% of patients. AIM: To determine the prognostic significance of scalp involvement in pemphigus vulgaris and pemphigus foliaceus. MATERIAL AND METHODS: A total of 75 patients (46 with pemphigus vulgaris, 29 with pemphigus foliaceus) were included into this prospective study. The following clinical data were analyzed: Pemphigus Disease Area Index, time to complete clinical remission and duration of complete clinical remission. Indirect immunofluorescence and enzyme-linked immunosorbent assay were performed to monitor serum pemphigus antibodies. RESULTS: Scalp involvement was observed in 30/46 (65.2%) patients with pemphigus vulgaris and 28/29 (96.6%) patients with pemphigus foliaceus. A positive correlation was found between scalp involvement and general disease severity as measured by the Pemphigus Disease Area Index (r = 0.7, p < 0.05). The time required to achieve a complete clinical remission in patients with and without scalp involvement was 39.1 ±47.1 and 9.1 ±7.8 months, respectively. The duration of complete clinical remission was 14.1 ±17.4 and 105.7 ±108.8 months, respectively. The respective time required to achieve serological remission was 37.7 ±58.5 and 15.5 ±18.8 months, whereas the duration of serological remission was 9.2 ±18.8 and 39.1 ±60.1 months, respectively. The average concentration of anti-desmoglein 1 autoantibodies was significantly higher in patients with scalp involvement compared to patients without scalp involvement (109.9 ±68.0 U/ml and 21.3 ±39.4 U/ml). CONCLUSIONS: Scalp involvement in pemphigus is associated with a higher disease severity, longer time required to achieve complete clinical and serological remission and may indicate the need for a more aggressive therapeutical approach.

The role of allogenic keratin-derived dressing in wound healing in a mouse model.

Keratin is an interesting protein needed for wound healing and tissue recovery. We have recently proposed a new, simple and inexpensive method to obtain fur and hair keratin-derived biomaterials suitable for medical application. The aim of the study was to evaluate the role of the fur keratin-derived protein (FKDP) dressing in the allogenic full-thickness surgical skin wound model. The data obtained using scanning electron microscopy showed that employed processed biomaterial had higher surface porosity compared with control raw material. From the MTS test, it was found keratin biomaterial is not only toxic to the NIH/3T3 cell line (p < 0.05), but also enhances cell proliferation compared with the control. In vivo studies have shown keratin dressings are tissue biocompatible, accelerate wound closure and epithelialization to the statistically significant differences on day 5 (p < 0.05) in comparison to control wounds. Histological examination revealed, that in FKDP-treated wounds the inflammatory response contained predominantly macrophages whilst their morphological untreated variants showed mixed cell infiltrates rich in neutrophils. Predominant macrophages based response creates more favorable environment for healing. In FKDP-dressed wounds the number of microhemorrhages was also significantly decreased (p < 0.05) as compared with undressed wounds. Applied keratin dressing favors reconstruction of a more regular skin structure and assures better cosmetic effect in terms of scar formation and appearance. In conclusion, fur keratin-derived protein dressings significantly accelerated wound healing in the mouse model. Further studies are needed to determine the molecular mechanisms involved in the multilayer wound healing process and to assess the possible use of these dressings for medical purposes.

Mice, rats, and guinea pigs differ in FMOs expression and tissue concentration of TMAO, a gut bacteria-derived biomarker of cardiovascular and metabolic diseases.

INTRODUCTION: Increased plasma trimethylamine oxide (TMAO) is observed in cardiovascular and metabolic diseases, originating from the gut microbiota product, trimethylamine (TMA), via flavin-containing monooxygenases (FMOs)-dependent oxidation. Numerous studies have investigated the association between plasma TMAO and various pathologies, yet limited knowledge exists regarding tissue concentrations of TMAO, TMAO precursors, and interspecies variability. METHODS: Chromatography coupled with mass spectrometry was employed to evaluate tissue concentrations of TMAO and its precursors in adult male mice, rats, and guinea pigs. FMO mRNA and protein levels were assessed through PCR and Western blot, respectively. RESULTS: Plasma TMAO levels were similar among the studied species. However, significant differences in tissue concentrations of TMAO were observed between mice, rats, and guinea pigs. The rat renal medulla exhibited the highest TMAO concentration, while the lowest was found in the mouse liver. Mice demonstrated significantly higher plasma TMA concentrations compared to rats and guinea pigs, with the highest TMA concentration found in the mouse renal medulla and the lowest in the rat lungs. FMO5 exhibited the highest expression in mouse liver, while FMO3 was highly expressed in rats. Guinea pigs displayed low expression of FMOs in this tissue. CONCLUSION: Despite similar plasma TMAO levels, mice, rats, and guinea pigs exhibited significant differences in tissue concentrations of TMA, TMAO, and FMO expression. These interspecies variations should be considered in the design and interpretation of experimental studies. Furthermore, these findings may suggest a diverse importance of the TMAO pathway in the physiology of the evaluated species.

Spontaneously hypertensive rats exhibit increased liver flavin monooxygenase expression and elevated plasma TMAO levels compared to normotensive and Ang II-dependent hypertensive rats.

Background: Flavin monooxygenases (FMOs) are enzymes responsible for the oxidation of a broad spectrum of exogenous and endogenous amines. There is increasing evidence that trimethylamine (TMA), a compound produced by gut bacteria and also recognized as an industrial pollutant, contributes to cardiovascular diseases. FMOs convert TMA into trimethylamine oxide (TMAO), which is an emerging marker of cardiovascular risk. This study hypothesized that blood pressure phenotypes in rats might be associated with variations in the expression of FMOs. Methods: The expression of FMO1, FMO3, and FMO5 was evaluated in the kidneys, liver, lungs, small intestine, and large intestine of normotensive male Wistar-Kyoto rats (WKY) and two distinct hypertensive rat models: spontaneously hypertensive rats (SHRs) and WKY rats with angiotensin II-induced hypertension (WKY-ANG). Plasma concentrations of TMA and TMAO were measured at baseline and after intravenous administration of TMA using liquid chromatography-mass spectrometry (LC-MS). Results: We found that the expression of FMOs in WKY, SHR, and WKY-ANG rats was in the descending order of FMO3 > FMO1 >> FMO5. The highest expression of FMOs was observed in the liver. Notably, SHRs exhibited a significantly elevated expression of FMO3 in the liver compared to WKY and WKY-ANG rats. Additionally, the plasma TMAO/TMA ratio was significantly higher in SHRs than in WKY rats. Conclusion: SHRs demonstrate enhanced expression of FMO3 and a higher plasma TMAO/TMA ratio. The variability in the expression of FMOs and the metabolism of amines might contribute to the hypertensive phenotype observed in SHRs.

Determination of Pathogens by Electrophoretic and Spectrometric Techniques.

In modern medical diagnostics, where analytical chemistry plays a key role, fast and accurate identification of pathogens is becoming increasingly important. Infectious diseases pose a growing threat to public health due to population growth, international air travel, bacterial resistance to antibiotics, and other factors. For instance, the detection of SARS-CoV-2 in patient samples is a key tool to monitor the spread of the disease. While there are several techniques for identifying pathogens by their genetic code, most of these methods are too expensive or slow to effectively analyze clinical and environmental samples that may contain hundreds or even thousands of different microbes. Standard approaches (e.g., culture media and biochemical assays) are known to be very time- and labor-intensive. The purpose of this review paper is to highlight the problems associated with the analysis and identification of pathogens that cause many serious infections. Special attention was paid to the description of mechanisms and the explanation of the phenomena and processes occurring on the surface of pathogens as biocolloids (charge distribution). This review also highlights the importance of electromigration techniques and demonstrates their potential for pathogen pre-separation and fractionation and demonstrates the use of spectrometric methods, such as MALDI-TOF MS, for their detection and identification.

Biomaterials in Skin Wound Healing and Tissue Regenerations-An Overview.

Wound healing is a complex biological process [...].

Beneficial Effect of Wound Dressings Containing Silver and Silver Nanoparticles in Wound Healing-From Experimental Studies to Clinical Practice.

Impaired wound healing affects hundreds of million people around the world; therefore, chronic wounds are a major problem not only for the patient, but also for already overloaded healthcare systems. Chronic wounds are always very susceptible to infections. Billions of dollars are spent to discover new antibiotics as quickly as possible; however, bacterial resistance against antibiotics is rising even faster. For this reason, a complete shift of the antibacterial treatment paradigm is necessary. The development of technology has allowed us to rediscover well-known agents presenting antimicrobial properties with a better outcome. In this context, silver nanoparticles are a promising candidate for use in such therapy. Silver has many useful properties that can be used in the treatment of chronic wounds, such as anti-bacterial, anti-inflammatory, and anti-oxidative properties. In the form of nanoparticles, silver agents can work even more effectively and can be more easily incorporated into various dressings. Silver-based dressings are already commercially available; however, innovative combinations are still being discovered and very promising results have been described. In this review article, the authors focused on describing experimental and clinical studies exploring dressings containing either silver or silver nanoparticles, the results of which have been published in recent years.

Silk Fibroin Biomaterials and Their Beneficial Role in Skin Wound Healing.

The skin, acting as the outer protection of the human body, is most vulnerable to injury. Wound healing can often be impaired, leading to chronic, hard-to-heal wounds. For this reason, searching for the most effective dressings that can significantly enhance the wound healing process is necessary. In this regard, silk fibroin, a protein derived from silk fibres that has excellent properties, is noteworthy. Silk fibroin is highly biocompatible and biodegradable. It can easily make various dressings, which can be loaded with additional substances to improve healing. Dressings based on silk fibroin have anti-inflammatory, pro-angiogenic properties and significantly accelerate skin wound healing, even compared to commercially available wound dressings. Animal studies confirm the beneficial influence of silk fibroin in wound healing. Clinical research focusing on fibroin dressings is also promising. These properties make silk fibroin a remarkable natural material for creating innovative, simple, and effective dressings for skin wound healing. In this review, we summarise the application of silk fibroin biomaterials as wound dressings in full-thickness, burn, and diabetic wounds in preclinical and clinical settings.

Keratin Biomaterials in Skin Wound Healing, an Old Player in Modern Medicine: A Mini Review.

Impaired wound healing is a major medical problem. To solve it, researchers around the world have turned their attention to the use of tissue-engineered products to aid in skin regeneration in case of acute and chronic wounds. One of the primary goals of tissue engineering and regenerative medicine is to develop a matrix or scaffold system that mimics the structure and function of native tissue. Keratin biomaterials derived from wool, hair, and bristle have been the subjects of active research in the context of tissue regeneration for over a decade. Keratin derivatives, which can be either soluble or insoluble, are utilized as wound dressings since keratins are dynamically up-regulated and needed in skin wound healing. Tissue biocompatibility, biodegradability, mechanical durability, and natural abundance are only a few of the keratin biomaterials' properties, making them excellent wound dressing materials to treat acute and chronic wounds. Several experimental and pre-clinical studies described the beneficial effects of the keratin-based wound dressing in faster wound healing. This review focuses exclusively on the biomedical application of a different type of keratin biomaterials as a wound dressing in pre-clinical and clinical conditions.

Electrophoretic Determination of Trimethylamine (TMA) in Biological Samples as a Novel Potential Biomarker of Cardiovascular Diseases Methodological Approach.

In competitive athletes, the differential diagnosis between nonpathological changes in cardiac morphology associated with training (commonly referred to as "athlete's heart") and certain cardiac diseases with the potential for sudden death is an important and not uncommon clinical problem. The use of noninvasive, fast, and cheap analytical techniques can help in making diagnostic differentiation and planning subsequent clinical strategies. Recent studies have demonstrated the role of gut microbiota and their metabolites in the onset and the development of cardiovascular diseases. Trimethylamine (TMA), a gut bacteria metabolite consisting of carnitine and choline, has recently emerged as a potentially toxic molecule to the circulatory system. The present work aims to develop a simple and cost-effective capillary electrophoresis-based method for the determination of TMA in biological samples. Analytical characteristics of the proposed method were evaluated through the study of its linearity (R2 > 0.9950) and the limit of detection and quantification (LOD = 1.2 µg/mL; LOQ = 3.6 µg/mL). The method shows great potential in high-throughput screening applications for TMA analysis in biological samples as a novel potential biomarker of cardiovascular diseases. The proposed electrophoretic method for the determination of TMA in biological samples from patients with cardiac disease is now in progress.

Genetically determined hypertensive phenotype affects gut microbiota composition, but not vice versa.

OBJECTIVES: Research suggests reciprocal crosstalk between the host and gut bacteria. This study evaluated the interaction between gut microbiota and arterial blood pressure (BP) in rats. METHODS: Continuous telemetry recordings of BP were started in 7-week-old normotensive Wistar--Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Two weeks later, half of the WKY and SHR were subjected to cross-transplantation of fecal matter, with stools harvested from either WKY or SHR and BP measurements until the age of 14 weeks. The composition of gut bacteria was assessed through analysis of the bacterial 16S ribosomal RNA gene sequence. The concentration of microbiota-derived metabolites was evaluated using HPLC-MS. RESULTS: There was a significant difference between WKY and SHR in the composition of gut bacteria at the start and end of the study. This was accompanied by significant histological differences in the colon. SHR, but not WKY, showed a gradual increase in BP throughout the experiment. For both WKY and SHR, there was no significant difference in BP or metabolic parameters between animals receiving fecal transplantation from either SHR or WKY. CONCLUSION: Genetically induced hypertension in SHR is associated with alterations in the composition of gut bacteria and histological morphology of the colon. An inter-strain fecal transplant does not affect BP and does not produce long-term changes in gut bacteria composition. We propose that the impact of the host genotype and/or phenotype on the gut bacteria may be greater than the impact of the gut bacteria on the host BP.