Do Curdlan Hydrogels Improved with Bioactive Compounds from Hop Exhibit Beneficial Properties for Skin Wound Healing?

Green synthesis of Ag/V2O5 and Ag/V2O5-curdlan nanocomposites from Sargassum latifolium extract for enhanced antimicrobial and antioxidant activities

The emergence of clinic-isolated bacteria and their ability to develop resistance mechanisms against conventional antimicrobials highlights the urgent need for novel, sustainable antimicrobial agents. This study explores the synthesis of Ag/V2O5 nanocomposites (NCs) using Sargassum latifolium extract, which is incorporated into a curdlan biocompatible matrix. The developed nanocomposites are evaluated for their antioxidant and antimicrobial activities, with a particular focus on their effectiveness against pathogenic bacteria. The applied method in this work combines green synthesis with the process of uniform distribution of nanoparticles to a biocompatible polymer, which is a way forward towards the design of efficient biocompatible antimicrobial systems. The Ag/V2O5 nanoparticles prepared with green synthesis were characterized by UV-Vis absorption, FTIR, XRD, SEM, EDX, zeta potential, DLS, and TEM. It has also been established that the antimicrobial property of the curdlan matrix has been enhanced with the addition of Ag/V2O5 nanoparticles in the incorporated curdlan composites. Ag/V2O5-curdlan also showed significantly enhanced antimicrobial activity against Gram-negative bacteria and Gram-positive bacteria thus implying enhanced antimicrobial action of the prepared nanocomposite by increasing the size of the bacterial zone of inhibition from 14.0 to 18.0 mm. Besides, the curdlan NC in the presence of Ag/V2O5 demonstrated an even lower value of MIC against Rhizoctonia solani (140.156 μg/mL) in comparison with Ag/V2O5 NC (226.413 μg/mL) thus predicting Augmented antifungal activity. Through performing TEM analysis, we have observed significant morphological changes in R. solani strain when the Ag/V2O5-curdlan NC was used. However, the Ag/V2O5-curdlan NC had a notably high antioxidant activity with IC50 of 0.302 mg/mL to DPPH radical scavenging assay. These results reaffirm the enhancement in antimicrobial properties when Ag/V2O5 and curdlan work together and agree with the objective of this work to propose novel and worthwhile nanomaterials for potentially applicable areas like food packaging or agriculture with insignificant harm to the environment.

Modern Approach to Testing the Biocompatibility of Osteochondral Scaffolds in Accordance with the 3Rs Principle─Preclinical In Vitro, Ex Vivo, and In Vivo Studies Using the Biphasic Curdlan-Based Biomaterial

The aim of this work is to provide a comprehensive set of biological tests to assess the biomedical potential of novel osteochondral scaffolds with methods proposed to comply with the 3Rs principle, focusing here on a biphasic Curdlan-based osteochondral scaffold as a promising model biomaterial. In vitro experiments include the evaluation of cytotoxicity, mutagenicity, and genotoxicity referring to ISO standards, the assessment of the viability and proliferation of human chondrocytes and osteoblasts, and the estimation of inflammation after direct contact of biomaterials with human macrophages. Ex vivo experiments include assessments of the response of the surrounding osteochondral tissue after incubation with the implanted biomaterial. In vivo experiments involve an evaluation of the toxicity and regenerative potential of the biomaterial in zebrafish (larvae and adults) and in osteochondral defects in dogs (veterinary patients). The applied set of tests allows us to show that the Curdlan-based scaffold does not induce cytotoxicity (cell viability close to 100%), mutagenicity (the level of reversion is not 2× higher compared to the control), and genotoxicity (it does not exhibit any change in chromosomal aberration; the frequency of micronuclei, micronucleated binucleated cells, and cytokinesis-block proliferation index is comparable to the control; moreover, it does not cause the formation of comets in cells). This biomaterial also promotes the viability and proliferation of chondrocytes and osteoblasts (the OD values between the fourth and seventh day of incubation increase by approximately 1.6×). The Curdlan-based scaffold stimulates only a transient inflammatory response in vitro and ex vivo. This biomaterial does not cause Danio rerio larvae malformation and also enables proper regeneration of the caudal fin in adults. Finally, it supports the regeneration of an osteochondral defect in veterinary patients. Thus, this is a proposal to use alternative methods for biological assessment of osteochondral scaffolds as opposed to commonly used tests using large numbers of laboratory animals.

Recent innovations (2020-2023) in the approaches for the chemical functionalization of curdlan and pullulan: A mini-review

Chemical modification represents a highly efficacious approach for enhancing the physicochemical characteristics and biological functionalities of natural polysaccharides. However, not all polysaccharides have considerable pharmacologic activity; so, appropriate chemical modification strategies can be selected in accordance with the distinct structural properties of polysaccharides to aid in improving and encouraging the presentation of their biological activities. Hence, there has been a growing interest in the chemical alteration of polysaccharides due to their various properties such as antioxidant, anticoagulant, antiviral, anticancer, biomedical, antibacterial, and immunomodulatory effects. This paper offers a comprehensive examination of recent scientific advancements produced over the past four years in the realm of unique chemical and functional modifications in curdlan and pullulan structures. This review aims to provide readers with an overview of the structural activity correlations observed in the backbone structures of curdlan and pullulan, as well as the diverse chemical modification processes employed for these polysaccharides. Additionally, the review aims to examine the effects of combining various bioactive molecules with chemically modified curdlan and pullulan and explore their potential applications in various important fields.

Recent Achievements in the Development of Biomaterials Improved with Platelet Concentrates for Soft and Hard Tissue Engineering Applications

Platelet concentrates such as platelet-rich plasma, platelet-rich fibrin or concentrated growth factors are cost-effective autologous preparations containing various growth factors, including platelet-derived growth factor, transforming growth factor β, insulin-like growth factor 1 and vascular endothelial growth factor. For this reason, they are often used in regenerative medicine to treat wounds, nerve damage as well as cartilage and bone defects. Unfortunately, after administration, these preparations release growth factors very quickly, which lose their activity rapidly. As a consequence, this results in the need to repeat the therapy, which is associated with additional pain and discomfort for the patient. Recent research shows that combining platelet concentrates with biomaterials overcomes this problem because growth factors are released in a more sustainable manner. Moreover, this concept fits into the latest trends in tissue engineering, which include biomaterials, bioactive factors and cells. Therefore, this review presents the latest literature reports on the properties of biomaterials enriched with platelet concentrates for applications in skin, nerve, cartilage and bone tissue engineering.

Biopolymers for Enhanced Health Benefits

The definition of the term biopolymer is often controversial, and there is no clear distinction between "biopolymers", "bioplastics", and "bio-based polymers" [...].