Biopolymers-Based Macrogels with Applications in the Food Industry: Capsules with Berry Juice for Functional Food Products.

The present study focused on the development of gel-based capsules from sodium alginate and the fresh juice from different berries: chokeberry, sea buckthorn, and blueberry. Obtained through the extrusion method, the macrocapsules were added into yogurt, a well-known and consumed dairy product. In order to establish the changes that can occur for the food product, the samples were tested over 7 and 15 days of storage in refrigeration conditions. According to the results, the antioxidant activity increased during storage and gels can represent a good option for bioactive substances' encapsulation. Sensorial analysis performed indicated that consumers are open to consuming yogurt berry capsules and, according to the results observed in the scientific literature, they no longer rejected the product due to the bitterness and sourness of sea buckthorn or aronia. Sea buckthorn capsules were brighter (L*) than chokeberry and blueberry capsules due to carotene content and dark colors. Minimal diameter variations and small standard deviations (SD = 0.25/0.33) suggest that extrusion methods and the Caviar box are good for gel capsule development. Yogurt luminosity varied with capsules; control had the highest, followed by sea buckthorn yogurt. Samples with chokeberry and blueberry (dark) capsules had lower luminosity. Over 8 and 15 days, luminosity slightly decreased, while a* and b* (hue and saturation) increased. Post-storage, the sample with chokeberry capsules showed a light purple color, indicating color transfer from capsules, with increased antioxidant activity. Differences between the samples and control were less pronounced in the sample with sea buckthorn capsules. Values for color differences between yogurt samples during the storage period revealed the most significant difference during the first storage period (day 1-8), with blueberries showing the lowest difference, indicating the stability of the blueberry capsules' wall during storage.

Innovative Materials with Possible Applications in the Wound Dressings Field: Alginate-Based Films with Moringa oleifera Extract.

For a long time, biopolymers have proven their effectiveness in the development of materials with various applications, lately those intended for the biomedical and pharmaceutical industries, due to their high biocompatibility and non-toxic, non-allergenic, and non-immunogenic nature. The ability to incorporate various active substances in this matrix has yielded materials with characteristics that are far superior to those of classic, conventional ones. The beneficial effects of consuming Moringa oleifera have promoted the use of this plant, from Ayurvedic to classical medicine. The addition of such compounds in the materials intended for the treatment of surface wounds may represent the future of the development of innovative dressings. This study followed the development of materials based on sodium alginate and moringa powder or essential oil for use as dressings, pads, or sheets. Thus, three materials with the addition of 10-30% moringa powder and three materials with the addition of 10-30% essential oil were obtained. The data were compared with those of the control sample, with sodium alginate and plasticizer. The microtopography indicated that the materials have a homogeneous matrix that allows them to incorporate and maintain natural compounds with prolonged release. For example, the sample with 30% moringa essential oil kept its initial shape and did not disintegrate, although the swelling ratio value reached 4800% after 20 min. After testing the mechanical properties, the same sample had the best tensile strength (TS = 0.248 MPa) and elongation (31.41%), which is important for the flexibility of the dressing. The same sample exhibited a very high antioxidant capacity (60.78% inhibition). The materials obtained with moringa powder added presented good values of physical and mechanical properties, which supports their use as wound dressings for short-term application and the release of embedded compounds. According to the obtained results, all the biopolymeric materials with moringa added can be used as dressings for different wound types.

The Use of Bioactive Compounds in Hyperglycemia- and Amyloid Fibrils-Induced Toxicity in Type 2 Diabetes and Alzheimer's Disease.

It has become increasingly apparent that defective insulin signaling may increase the risk for developing Alzheimer's disease (AD), influence neurodegeneration through promotion of amyloid formation or by increasing inflammatory responses to intraneuronal ß-amyloid. Recent work has demonstrated that hyperglycemia is linked to cognitive decline, with elevated levels of glucose causing oxidative stress in vulnerable tissues such as the brain. The ability of ß-amyloid peptide to form ß-sheet-rich aggregates and induce apoptosis has made amyloid fibrils a leading target for the development of novel pharmacotherapies used in managing and treatment of neuropathological conditions such as AD-related cognitive decline. Additionally, deposits of ß-sheets folded amylin, a glucose homeostasis regulator, are also present in diabetic patients. Thus, therapeutic compounds capable of reducing intracellular protein aggregation in models of neurodegenerative disorders may prove useful in ameliorating type 2 diabetes mellitus symptoms. Furthermore, both diabetes and neurodegenerative conditions, such as AD, are characterized by chronic inflammatory responses accompanied by the presence of dysregulated inflammatory biomarkers. This review presents current evidence describing the role of various small bioactive molecules known to ameliorate amyloidosis and subsequent effects in prevention and development of diabetes and AD. It also highlights the potential efficacy of peptide-drug conjugates capable of targeting intracellular targets.

Zinc Binding to NAP-Type Neuroprotective Peptides: Nuclear Magnetic Resonance Studies and Molecular Modeling.

Aggregation of amyloid-ß peptides (Aß) is a hallmark of Alzheimer's disease (AD), which is affecting an increasing number of people. Hence, there is an urgent need to develop new pharmaceutical treatments which could be used to prevent the AD symptomatology. Activity-dependent neuroprotective protein (ADNP) was found to be deficient in AD, whereas NAP, an 8-amino-acid peptide (1NAPVSIPQ8) derived from ADNP, was shown to enhance cognitive function. The higher tendency of zinc ion to induce Aß aggregation and formation of amorphous aggregates is also well-known in the scientific literature. Although zinc binding to Aß peptides was extensively investigated, there is a shortage of knowledge regarding the relationship between NAP peptide and zinc ions. Therefore, here, we investigated the binding of zinc ions to the native NAP peptide and its analog obtained by replacing the serine residue in the NAP sequence with tyrosine (1NAPVYIPQ8) at various molar ratios and pH values by mass spectrometry (MS) and nuclear magnetic resonancespectroscopy (NMR). Matrix-assisted laser desorption/ionization time-of-flight (MALDI ToF) mass spectrometry confirmed the binding of zinc ions to NAP peptides, while the chemical shift of Asp1, observed in 1H-NMR spectra, provided direct evidence for the coordinating role of zinc in the N-terminal region. In addition, molecular modeling has also contributed largely to our understanding of Zn binding to NAP peptides.

Direct evidence for binding of aluminum to NAP anti-amyloid peptide and its analogs.

NAP (NAPVSIPQ) is a small peptide derived from the activity-dependent neuroprotective protein (ADNP), which provides neuroprotection against amyloid-ß peptide toxicity associated with Alzheimer disease. Several metal ions are able to promote the formation of amyloid-ß peptide oligomers and protofibrils in human brain tissue. Although the relationship between metal ions and amyloid-ß peptide peptides is extensively investigated, that with the NAP peptide is less understood. Nevertheless, our previous research revealed unexpected iron binding to NAP peptide and its analogs. However, a link between aluminum ions, Alzheimer disease and amyloid-ß peptide or NAP peptides still remains controversial. Therefore, we have investigated the possible binding of aluminum ions to NAP peptide and its four analogs. Indeed, MALDI-ToF mass spectrometry (MS), including MS/MS study, and Fourier transform infrared (FT-IR) spectroscopy revealed an unexpected pattern of aluminum ion binding to both NAP peptide and its analogs. Our results have been discussed with respect to NAP protection against Alzheimer disease-related neurotoxicity.

Stoichiometry of Heavy Metal Binding to Peptides Involved in Alzheimer's Disease: Mass Spectrometric Evidence.

Mass spectrometry is a powerful analytical technique becoming increasingly important in different biomedical research area. Mass spectrometric based methods were developed and applied to detect and identify multiple metal ion complexes of peptides and proteins with high sensitivity and high mass accuracy. Aggregation of amyloid-ß (Aß) peptides is one of the main pathological features of Alzheimer's disease (AD), and some metal ions seem to play a key role in AD pathogenesis. Consequently, mass spectrometry was used to investigate heavy metal binding to AD-related peptides. Therefore, the purpose of this chapter is to review the methodology and application of identifying coordination chemistry and binding properties of several metal ion-binding sites to synthetic ß-amyloid (Aß) and anti-amyloid model peptides. The selective metal-amyloid-ß peptide interaction studies using (a) Matrix-assisted laser desorption/ionization mass spectrometry (MALDI); (b) Electrospray ionization mass spectrometry (ESI-MS), and (c) Tandem mass spectrometry (MS/MSn) will be reported.