Concentrations Of Trypsin Research Articles

Effects of trypsin and pepsin detection on chronic otitis media with effusion

Chronic otitis media with effusion (COME) is a common cause of hearing loss in children and adults. Laryngopharyngeal reflux (LPR) is often overlooked in the clinical management of COME complicated by LPR. This study aimed to investigate the presence and concentration of trypsin and pepsin in the middle ear effusion (MEE), as well as the recurrence rate of otitis media with effusion (OME) in COME patients with trypsin-/pepsin-positive MEE after acid-suppressive treatment (AST). In this study, trypsin and pepsin were found in the MEE of COME patients. Follow-up results showed that the recurrence rate of OME within 1 year was significantly lower in the AST group than in the non-AST group. Taken together, patients with COME can be offered pepsin detection of MEE, and if the pepsin test is positive, acid-suppressing drugs such as proton pump inhibitors could be recommended to prevent the recurrence of OME.

Optimization of the alcalase and trypsin hydrolysis conditions of an isolated protein from Scenedesmus obliquus microalgae and characterization of its functional properties

This study focused on fine-tuning the enzymatic hydrolysis variables, specifically the duration and enzyme concentrations of alcalase and trypsin, for Scenedesmus obliquus protein using response surface methodology (RSM) with a central composite design (CCD). The aim was to characterize the amino acids, separate hydrolysates based on molecular weight, and assess functional activities such as antioxidant, emulsifying, fat-binding, and foaming capacities. After fractionating the hydrolysates, bioactivities were evaluated through standard assays. The optimal hydrolysis conditions—10.24 g/100 mL alcalase and 2.56 g/100 mL trypsin—yielded the highest protein extraction. Peptides smaller than 5 kDa demonstrated 80% DPPH inhibition and superior fat-binding capacity. Emulsifying capacity peaked at 112 m2/g for peptides under 10 kDa, and the highest foaming index was observed for peptides below 5 kDa. The application of RSM effectively optimized the hydrolysis of microalgal protein isolates for maximum efficiency, highlighting microalgae's potential as a sustainable source of functional ingredients.

New mechanistic insights of nanoplastics synergistic cadmium induced overactivation of trypsin: Joint analysis from protein multi-level conformational changes and computational modeling

Nanoplastics (NPs) are emerging global contaminants that can exacerbate the animal toxicity and cytotoxicity of cadmium (Cd). However, the mechanisms by which NPs influence the toxic effects of Cd on key functional proteins within the body remain unknown. In this study, trypsin, a protein that is prone to coexist with NPs in the digestive tract, was selected as the target protein. The effects and mechanisms of NPs on Cd2+-induced structural damage at multiple levels and alterations in the biological function of trypsin were investigated using multi-spectroscopy techniques, enzyme activity assays, and computational modeling. Results indicated that the Cd2+-induced decrease and red shift of the trypsin backbone peak were exacerbated by the presence of NPs, leading to more serve backbone loosening. Furthermore, compared to Cd2+, NPs@Cd2+ caused a more pronounced reduction in the α-helix content of trypsin. These structural changes led to the opening of the trypsin pocket and the overactivation of the enzyme (NPs@Cd2+: 227.22%; Cd2+: 53.35%). Ultimately, the formation of a “protein corona” around NPs@Cd2+ and the metal contact of Cd2+ to the trypsin surface were identified as the mechanisms by which NPs enhanced the protein toxicity of Cd2+. This study elucidates, for the first time, the effects and underlying mechanisms of NPs on the toxicity of key functional proteins of Cd2+. These findings offer novel mechanistic insights and critical evidence essential for evaluating the risks associated with NPs.

Assessment of the hormesis effect and toxic damage of short-term low-dose aflatoxin B1 in grass carp (Ctenopharyngodon idellus)

The present study was conducted to evaluate the hormesis and toxicity of short-term low-dose aflatoxin B1 in grass carp (Ctenopharyngodon idellus). Triplicate isonitrogenous and isocaloric aflatoxin B1 diets—CD (control, 0 ug/kg), D1 (20 ug/kg), and D2 (500 ug/kg)—were prepared and fed to grass carp with an initial mean body weight of (15.2 ± 0.1) g for 56 days. The results showed that the weight gain rate and specific growth rate of grass carp fed diet D2 were significantly higher, and the feed coefficient and crude fat content of the whole body were significantly lower (P < 0.05) compared with those fed diet CD. Serum superoxide dismutase content of grass carp fed D1 diet increased significantly (P < 0.05) with an increasing dose of aflatoxin B1, but when the dose reached 500 ug/kg (D2), serum superoxide dismutase, complement C3, and immunoglobulin M of grass carp decreased significantly (P < 0.05), while malondialdehyde increased significantly (P < 0.05). After short-term feeding of aflatoxin B1-containing diets (D1 and D2), liver body index, visceral body index, serum total cholesterol, triglyceride, and urea nitrogen content of grass carp increased significantly (P < 0.05), total bile acid secretion decreased significantly (P < 0.05), and structural damages such as increase in vacuoles, organizational structure loosening, and nucleus translocation were observed in the liver. Meanwhile, liver function indexes such as serum alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase increased significantly with the increase of aflatoxin B1 dose (P < 0.05). In addition, the height of intestinal villi, crypt depth, villus–crypt ratio, and tubular cell number, as well as the content of trypsin and lipase activities in the intestine of grass carp in the D2 group, were significantly higher than those in the CD group (P < 0.05). In conclusion, after a short-term intake of low doses of aflatoxin B1 (≤500 ug/kg), the toxicological damage of aflatoxin B1 was pronounced, although it produced a certain degree of hormesis on the growth performance and intestinal structure and function of grass carp. At a dose of 20 ug/kg, the non-specific immune system and liver structure and function of grass carp showed obvious toxic damage.

Applying bimetallic gold/silver nanoclusters and gold nanoparticles for dairy trypsin and inhibitor analysis via inner-filter approach

Trypsin, a globular protein hydrolase, catalyzes the hydrolysis of peptide bonds at carboxyl groups of arginine and lysine residues, its detection holds paramount significance in the dairy industry, aiding in the diagnosis, management of animal diseases, and preservation of dairy products. This study introduces a highly sensitive fluorometric detection platform utilizing bimetallic gold/silver nanoclusters (Au/Ag NCs) and gold nanoparticles (AuNPs) in an "off-on-off" configuration for precise quantification of dairy trypsin and trypsin inhibitors. This fluorescence variation is leveraged to determine the concentration of trypsin and its inhibitors. Under optimal experimental conditions, the detection of trypsin demonstrates a linear range of 5 ∼ 2000 ng·mL−1 , a lowest detection limit of 1.18 ng·mL−1, and an observed IC50 of 5.94 μg·mL−1 for the soybean trypsin inhibitor (STI). Therefore, it could be inferred that the development of a fluorescence sensing platform presents an important basis for the detection of dairy trypsin.

Impact of trypsin on cell cytoplasm during detachment of cells studied by terahertz sensing

Trypsin is a very common enzyme used in cell culture to harvest cells by cleaving the proteins responsible for cell adhesion. However, trypsin also induces undesirable effects on cells, such as altering membrane proteins and the cytoskeleton, changing the composition of the cytoplasm and the cell volume, and even leading to cell death when used improperly. Using attenuated total reflection in the terahertz domain, confocal microscopy, and the propidium iodide test, we quantified in real time the change in cytoplasmic content induced by trypsin proteolysis on Madin-Darby canine kidney epithelial cells. We have observed a cytoplasmic modification from the very first seconds of trypsinization, following the change of cell volume due to mechanical re-equilibrium of the membrane. We found that the cytoplasmic alteration is associated with a transfer of small solutes: electrolytes and metabolites. We also found a very good nonlinear correlation between the side effects monitored by terahertz sensing and the cell height, regardless of the dependence of the cell height on trypsin concentration and exposure time.

Fucoidan alleviates the inhibition of protein digestion by chitosan and its oligosaccharides

Chitosan (CTS) and chitosan oligosaccharides (COS) have been widely applied in food industry due to their bioactivities and functions. However, CTS and COS with positive charges could interact with proteins, such as whey protein isolate (WPI), influencing their digestion. Interaction among CTS/COS, FUC, and WPI/enzymes was studied by spectroscopy, chromatography, and chemical methods in order to reveal the role of FUC in relieving the inhibition of protein digestibility by CTS/COS and demonstrate the action mechanisms. As shown by the results, the addition of FUC increased degree of hydrolysis (DH) and free protein in the mixture of CTS and WPI to 3.1-fold and 1.8-fold, respectively, while raise DH value and free protein in the mixture of COS and WPI to 6.7-fold and 1.2-fold, respectively. The interaction between amino, carboxyl, sulfate, and hydroxyl groups from carbohydrates and protein could be observed, and notably, FUC could interact with CTS/COS preferentially to prevent CTS/COS from combining with WPI. In addition, the addition of FUC could also relieve the combination of CTS to trypsin, increasing the fluorescence intensity and concentration of trypsin by 83.3 % and 4.8 %, respectively. Thus, the present study demonstrated that FUC could alleviate the inhibitory effect of CTS/COS on protein digestion.

Improvement of protocol for detachment assays in B16F10 cells

B16F10 (B16) murine melanoma cells have the characteristic of strong adhesion to culture surfaces. The use of trypsin solutions in high doses to release this type of cell is not suitable. When B16F10 cells are released with high concentrations of trypsin they do not form a precipitate after centrifugation and consequently the cells will be lost when discarding the supernatant. To solve this problem, we established a solution with phosphate buffered saline (PBS) and ethylenediaminetetraacetic acid (EDTA) at low trypsin concentrations. Finally, we verified the efficiency of this solution on the quantity of cells recovered after centrifugation.

Optimization of Enzymatic and Chemical Decellularization of Native Porcine Heart Valves for the Generation of Decellularized Xenografts.

One of the most important medical interventions for individuals with heart valvular disease is heart valve replacement, which is not without substantial challenges, particularly for pediatric patients. Due to their biological properties and biocompatibility, natural tissue-originated scaffolds derived from human or animal sources are one type of scaffold that is widely used in tissue engineering. However, they are known for their high potential for immunogenicity. Being free of cells and genetic material, decellularized xenografts, consequently, have low immunogenicity and, thus, are expected to be tolerated by the recipient's immune system. The scaffold ultrastructure and ECM composition can be affected by cell removal agents. Therefore, applying an appropriate method that preserves intact the structure of the ECM plays a critical role in the final result. So far, there has not been an effective decellularization technique that preserves the integrity of the heart valve's ultrastructure while securing the least amount of genetic material left. This study demonstrates a new protocol with untraceable cells and residual DNA, thereby maximally reducing any chance of immunogenicity. The mechanical and biochemical properties of the ECM resemble those of native heart valves. Results from this study strongly indicate that different critical factors, such as ionic detergent omission, the substitution of Triton X-100 with Tergitol, and using a lower concentration of trypsin and a higher concentration of DNase and RNase, play a significant role in maintaining intact the ultrastructure and function of the ECM.

Probing the interaction mechanisms between sunset yellow dye and trypsin protein leading to amorphous aggregation under low pH conditions

Protein aggregation poses a significant concern in the field of food sciences, and various factors, such as synthetic food dyes, can contribute to protein aggregation. One such dye, Sunset Yellow (SY), is commonly employed in the food industry. Trypsin was used as a model protein to assess the impact of SY. We employed several biophysical techniques to examine the binding and aggregation mechanisms between SY and trypsin at different pHs. Results from intrinsic fluorescence measurements indicate a stronger interaction between SY and trypsin at pH 2.0 compared to pH 6.0. Turbidity data reveal trypsin aggregation in the presence of 0.05–3.0 mM SY at pH 2.0, while no aggregation was observed at pH 6.0. Kinetic data demonstrate a rapid, lag-phase-free SY-induced aggregation of trypsin. Circular dichroism analysis reveals that trypsin adopts a secondary structure in the presence of SY at pH 6.0, whereas at pH 2.0, the secondary structure was nearly lost with increasing SY concentrations. Furthermore, turbidity and kinetics data suggest that trypsin aggregation depends on trypsin concentrations and pH. Our study highlights potential health risks associated with the consumption of SY, providing insights into its impact on human health and emphasizing the necessity for further research in this field.

Photoelectrochemical quenching-recovery biosensor based on NSCQDs/Fe2O3@Bi2S3 for the detection of trypsin

BackgroundThe content of trypsin will change when pancreatic diseases occur, therefore developing a high-performance method for trypsin detection is of great significance for guiding patients on medication plans and improving their prognosis. Photoelectrochemical (PEC) analysis techniques have emerged as a solution to apply for bioassays. ResultsHerein, the Fe2O3@Bi2S3 and Nitrogen and sulfur co-doped carbon quantum dots (NSCQDs) were successfully synthesized by a hydrothermal method. Subsequently, NSCQDs/Fe2O3@Bi2S3 with a photocurrent amplification effect covered on fluorine-doped tin oxide (FTO) electrode as the substrate material and apoferritin (APO) as a bio-recognition element to quench the photocurrent of the substrate material which can be excited with light. Due to the decomposition specifically between APO and trypsin, the photocurrent response increased. The linear range for trypsin detection showed satisfied results from 2 to 1000 ng mL−1 under optimal conditions, with a detection limit of 0.42 ng mL−1 and a recovery rate of 97.41 %–103.02 %, enabling efficient quantitative analysis of trypsin. SignificanceIn this experiment, a PEC biosensor with simple operation, low detection limit, excellent selectivity and strong stability was successfully prepared, enabling quantitative analysis of trypsin in human serum samples through the quenching-recovery mechanism. It holds great significance for diagnosis and serves as a practical method for the detection of trypsin in the future.

An impedimetric sensor based on molecularly imprinted nanoparticles for the determination of trypsin in artificial matrices - towards point-of-care diagnostics.

A high-performance impedimetric sensing platform was designed to detect proteins by employing molecularly imprinted polymeric nanoparticles (nanoMIPs) as selective receptors. This was achieved via the combination of the nanoMIPs with a self-assembled thioctic acid (SAM-TA) monolayer onto screen-printed gold electrodes, providing stable covalent attachment of the selective binder to the transducer. Taguchi design has been modelled to achieve the optimal level of sensor fabrication parameters and to maximise the immobilisation of nanoMIPs and their response (e.g. the response of imprinted polymers compared with the non-imprinted control). The developed sensor was tested towards a range of concentrations of trypsin dissolved in ammonium acetate (pH = 6) and showed promising applicability in artificial saliva, with a recovery percentage between 103 and 107%.

Exploration of the antimicrobial activities of biocontrol agent Streptomyces strain h114 against Penicillium digitatum in citrus

Biocontrol is considerably crucial in phytopathogens management during postharvest fruit storage. In this study, assays were performed to screen beneficial microbes through the microorganisms which were isolated from the citrus rhizosphere soil, and to investigate the potential antifungal action modes towards Penicillium digitatum, the perpetrator of citrus green mold. Strain h114 was selected for its high controlling effect against citrus green mold pathogen, and it was phylogenetically identified as a Streptomyces monashensis isolate by whole genome analysis. Thereafter, a total of 35 secondary metabolite gene clusters which were responsible for the biosynthesis of antibiotics were found in the genome. The culture filtrates (CFS) fermented from strain h114 with incubation for 36 h in beef extract-peptone broth exhibited the strongest antifungal activity towards P. digitatum than filtrates obtained from other time points. Despite the susceptibilities to long time treated by boiled water and high concentration of trypsin, the 36 h fermented CFS showed relatively stable antagonism in room conditions. Further, its xylene-extracted crude compounds also displayed a bioactive effect to P. digitatum. CFS-treated P. digitatum cells exhibited degradation of mitochondria, accompanied by reduced expression of developmental regulatory genes PdBrlA and PdWetA. Moreover, CFS induced the fruit defense activities such as superoxide dismutase and peroxidase, and alleviated the virulence of P. digitatum in citrus. After CFS application, the expansion diameters of P. digitatum on artificially-wounded citrus fruit were reduced by 71.5% at most, and the disease incidence diminished by 62.7–72.9% compared to that of P. digitatum treated fruit alone. Taken together, strain h114 might be a promising bio-fungicide in postharvest citrus fruit handling.

A design of experiment approach for optimized production of encapsulated trypsin using nano spray drying: Comparative physicochemical and kinetic characterization

Enzymes are challenging to formulate due to their inherent instability, particularly in solution. This study aims to use the design of experiment (DOE) approach to develop spray-dried encapsulated trypsin nano-powder (TrySP) with maximum activity and stability using a Büchi B-90 nano spray dryer. A 53 full factorial design with 26 randomly ordered experiments was created to study the impact of process variables on the quality attributes of TrySP. The additive concentration (%), mesh cap size (μm), inlet temperature (T inlet) (°C), trypsin concentration (%), and additive type (Mannitol or trehalose) were selected as the independent variables. The dependent parameters were yield value, particle size, residual enzyme activity, and moisture content. Further, comparative physicochemical and kinetic characterization of TrySP was performed. TrySP had diverse qualities (yield value 60.2–96.8%, residual activity >90–50%, particle size 314–1030 nm, and moisture content 0.7–2.2%). Optimized TrySP exhibited 89% yield value and 95% residual activity in the presence of 8% (w/w) mannitol. Kcat of TypSP increased from 22.5/s to 25.6/s with improved operational and storage stabilities. The half-life (t 1/2) of TrySP showed 6 folds increase. Furthermore, TrySP activation energy increased from 45,918 J/mol to 94,491 J/mol. The sustainable model presented in this study enables the development of a thermostable, encapsulated trypsin nano-powder with physical and chemical properties that are optimized for various biotechnological industrial applications.

Cheaper, faster, simpler trypsin digestion for high-throughput targeted protein quantification

IntroductionLC-MS-based methods for protein quantification have a stigma of being relatively expensive and low-throughput. This is partly due to the cost and speed of trypsin digestion, which has primarily focused on advancements in research-based biomarker discovery applications that rely on protein/peptide identifications rather than clinical biomarker quantification. However, there is a need for simple, fast, and reproducibly efficient surrogate peptide recovery in clinical biomarker quantification. MethodsMultiple methodologies were evaluated to enhance tryptic digestion for the analysis of thyroglobulin, a prototypical serum protein biomarker. The main criteria for assessment were the yield and speed of formation of surrogate peptides. Various factors such as different additives, types of trypsin, microwave- and pressure-assisted systems, and enzyme concentration were considered as key variables, in addition to digestion time. ResultsIt was observed that digestion additives/denaturants had a significant impact on the speed and yield of digestion for each surrogate peptide. Increasing the concentration of trypsin alone was found to accelerate digestions appreciably for most surrogate peptides, without affecting the yield. However, the use of sequencing-grade trypsins and microwave/pressure-assisted systems did not offer significant advantages over the use of 'standard-grade' TPCK-treated trypsin in combination with a conventional incubator, once digestion time and additive had been optimized. ConclusionWe have dispelled the notion that trypsin digestion is inherently slow and expensive for targeted quantification of serum proteins. Additionally, we have established a groundwork for experimentation that can pave the way for the creation of efficient trypsin digestion protocols, aiming to optimize yield, speed, and cost. It is our hope that these advancements will promote the wider incorporation of such assays in clinical laboratories.

Bimetallic oxide Mg-Cu nanoparticles synthesis and application in photometric sensing of trypsin in the presence of tap water, ammonia, and glutamine

The concentration of biomolecules such as trypsin and ammonia in bodily fluids are indicators of health conditions including pancreatic diseases and acute liver failure respectively. The maximum UV-Visible intensity and wavelength shifts of Mg-Cu bimetallic oxide nanoparticles (BNPs) were found to be proportional to changes in trypsin and ammonia concentration. The BNPs could selectively detect trypsin in tap water containing ions, ammonia, and glutamine at concentrations as low as 0.0003%v/v. The synthesis of Mg-Cu BNPs was accomplished by ablating a mixture of Mg and Cu powders and Mg and Cu colloids using a Nd:YAG 1064 nm laser in isopropanol alcohol and HCl. The BNPs demonstrated higher optical absorbance intensity in the UV-Visible range compared to their monometallic constituents, making them more suitable for use in biochemical sensing of trypsin and ammonia. The BNPs exhibited a massive 730-fold increase in electrical conductivity compared to monometallic Mg nanoparticles (0.001 mS/cm vs. 0.73 mS/cm). Field emission scanning electron microscopy was used to visualize the NP morphologies, revealing pyramidal and quasi-spherical BNPs with diameters as small as 5 nm.

Pancreatic biomarkers: role in diabetes mellitus

Diabetes mellitus refers to a group of diseases that cause high blood sugar levels. The most common type is type 2 diabetes, which is caused by insulin resistance and inadequate insulin production. However, diabetes can also result from conditions affecting the exocrine pancreas. Both type 1 and type 2 diabetes patients may experience changes in their pancreatic exocrine function, leading to reduced levels of fecal elastase-1 in many cases. This review article focuses on the role of specific pancreatic biomarkers in diabetes mellitus, including cholecystokinin, trypsin, chymotrypsin, carboxypeptidase, amylase, lipase, secretin, elastase-1, and retinol-binding protein 4 about recent advances and discoveries, significant gaps in the literature, current debates, and potential directions for future research related to these biomarkers about diabetes mellitus. This review article discusses various biomarkers related to pancreatic exocrine and endocrine function and their implications in diabetes. It suggests that gut cholecystokinin may play a role in lowering glucose synthesis through a neural network and resistance to it could contribute to hyperglycemia in diabetic patients. It also discusses the use of various markers such as serum trypsin concentration, amylase and lipase levels, pancreatic elastase levels, and fasting secretin levels to assess pancreatic exocrine function. Additionally, the article explores the role of carboxypeptidase E in the endocrine and neurological systems and its association with disorders. Moreover, it also highlights the involvement of retinol-binding protein 4 in the development of type 2 diabetes and insulin resistance.

Effects of flow velocity on the growth performance, antioxidant activity, immunity and intestinal health of Chinese Perch (Siniperca chuatsi) in recirculating aquaculture systems.

The cultivation of Chinese Perch (Siniperca chuatsi) in recirculating aquaculture systems (RASs) has become a common trend. To explore the effect of flow velocity on the growth performance, antioxidant activity, immunity and intestinal health of Chinese Perch in RAS, 240 Chinese Perch with an initial weight of 70.66±0.34g were selected and randomly divided into 4 groups: control group [CK, 0 body length per second (bl/s)], low flow velocity (LF, 0.4 bl/s), middle flow velocity (MF, 0.8 bl/s) and high flow velocity (HF, 1.2 bl/s) for a 56-days experiment. The results showed that the flow velocity significantly increased the weight gain rate and feed intake in Chinese Perch. At 1.2 bl/s, the flow velocity increased the intestinal trypsin content and intestinal villus length. Furthermore, the relative expression of appetite-related genes showed a tendency to increase, and the relative expression of appetite-inhibiting genes had a significant decrease in HF. Regarding immune-related indicators, the activities of alanine aminotransferase (ALT) and aspartate transaminase (AST) were significantly higher in MF and HF. However, the activities of lysozyme (LZM) significantly decreased. Moreover, the activities of total superoxide dismutase (T-SOD) and catalase (CAT) were significantly higher in the CK group than in the other groups. Excessive flow velocity also caused the mRNA level of most immune-relevant genes to markedly decrease. With regard to intestinal health, the intestinal content sequencing results showed that MF could increase the intestinal diversity index of Chinese Perch. In addition, with increasing flow velocity, the relative abundance of Proteobacteria gradually increased, while the proportion of Firmicutes decreased. In conclusion, although the high flow velocity could promote growth, feeding, and digestion, inhibit fat deposition and increase the intestinal microbial abundance, the flow velocity caused stress, which leads to a decline in immunity and increases the death rate and the risk of intestinal disease in Chinese Perch. These findings provide theoretical support for the development of RASs for Chinese Perch.

Effect of trypsin on biochemical and functional properties of decellularized porcine articular cartilage

Objective: to study the effect of trypsin pretreatment in the porcine articular cartilage decellularization protocol on the ability to restore the biochemical composition and functional properties of the resulting finely dispersed tissue-specific scaffold when co-cultured with human adipose-derived stem cells (hADSCs).Materials and methods. Porcine articular cartilage was micronized to a maximum size of 250 μm. The resulting porcine articular cartilage microparticles (CMps) were treated with trypsin (0.05, 0.25, 0.50%) / EDTA solution at +37 °C for 24 hours. Then, the CMps were successively incubated for 24 hours in three surfactant solutions containing 0.1% sodium dodecyl sulfate and increasing concentration of Triton X-100 (1, 2, 3%) at room temperature and in DNase I solution at +37 °C for 48 hours. The degree of change in the biochemical composition and the ability of decellularized CMps (DCMps) scaffolds within cell-engineered constructs (CECs) to support hADSC adhesion and proliferation, as well as their potential ability to exert a stimulatory regenerative effect, were then assessed. DNA, glycosaminoglycans (GAGs) and collagen content in the DCMps and CECs were examined. The morphology of the samples was examined using histological and immunohistochemistry staining.Results. Histological analysis showed that there were no cells and detritus in the DCMp samples. Pretreatment of CMps samples гыштп a solution with the lowest content of trypsin (0.05%) / EDTA in the samples retained 5.14 ± 0.87 ng/mg DNA in the samples, while GAG content decreased to 5.34 ± 0.9 μg/mg and collagen to 154 ± 34 μg/mg. By day 28 of CEC cultivation, adherent cells had produced their own extracellular matrix (ECM) containing GAGs and collagen. The amount of DNA in it was 6.30 ± 0.11 μg/CEC and that of GAGs was 19.36 ± 0.73 μg/CEC.Conclusion. Pretreatment with trypsin allows achieving uniformly complete decellularized CMps. At the same time, onset of changes in the ECM composition indicates a decrease in the ability of hADSCs to synthesize GAGs and type II collagen during co-culturing with DCMps. The increased proliferative activity of adherent hADSCs, as well as the tissue specificity of the DCMp scaffold will allow further research towards a hydrogel matrix capable of enhancing the specific and stimulating regenerative potential when co-cultured with cells of the same phenotype.

Protein corona formed on the TiO2 nanoparticles promotes the hydrolysis of collagen in simulated gastrointestinal fluids

Titanium dioxide nanoparticles (TiO2 NPs) could interact with proteins in foods and gastrointestinal fluids, thus changing the properties and functions of proteins. Many research articles have only studied the interactions between TiO2 NPs and digestive enzymes or the gastrointestinal fate of TiO2 NPs without considering the effect of food matrix. Therefore, the interactions between TiO2 NPs and trypsin and its effects on the digestion of collagen in vitro were investigated. Results showed that the functionalization of amino acids (Asp, and Ser) significantly harmed the adsorption of trypsin by TiO2 NPs. The fluorescence quenching and isothermal titration calorimetry confirmed that the hydrogen bond and van der Waals force played an essential role in the interactions between TiO2 NPs and trypsin. The β-sheet content of trypsin bound to TiO2 NPs decreased from 52.40% to 50.73% while the random coil content increased from 20.20% to 22.63%. Binding sites were identified by molecular docking. Additionally, the digestibility of collagen was improved in vitro in the presence of TiO2 NPs analyzed by SDS-PAGE, hydroxyproline quantification, and the antioxidation of digested products. Hydroxyproline concentration increased by nearly 25% and ABTS radical scavenging rate increased by 50%. This study provides a new insight into the impact of nanoparticles on gastrointestinal digestion.