scholarly journals Adhesive Catechol-Conjugated Hyaluronic Acid for Biomedical Applications: A Mini Review

2020 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Jongho Kim ◽  
Chaemyeong Lee ◽  
Ji Hyun Ryu
Keyword(s):  
Hyaluronic Acid ◽  
Biomedical Applications ◽  
Therapeutic Effects ◽  
Intrinsic Properties ◽  
Tissue Adhesives ◽  
Adhesive Properties ◽  
Tissue Engineering Scaffolds ◽  
Polymer Backbone ◽  
Adhesion Properties ◽  
Basic Concepts

Recently, catechol-containing polymers have been extensively developed as promising materials for surgical tissue adhesives, wound dressing, drug delivery depots, and tissue engineering scaffolds. Catechol conjugation to the polymer backbone provides adhesive properties to the tissue and does not significantly affect the intrinsic properties of the polymers. An example of a catecholic polymer is catechol-conjugated hyaluronic acid. In general, hyaluronic acid shows excellent biocompatibility and biodegradability; thus, it is used in various medical applications. However, hyaluronic acid alone has poor mechanical and tissue adhesion properties. Catechol modification considerably increases the mechanical and underwater adhesive properties of hyaluronic acid, while maintaining its biocompatibility and biodegradability and enabling its use in several biomedical applications. In this review, we briefly describe the synthesis and characteristics of catechol-modified hyaluronic acid, with a specific focus on catechol-involving reactions. Finally, we discuss the basic concepts and therapeutic effects of catechol-conjugated hyaluronic acid for biomedical applications.

The Potential Applications of Hyaluronic Acid Hydrogels in Biomedicine

Drug Research ◽  
2019 ◽  
Vol 70 (01) ◽  
pp. 6-11 ◽  
Author(s):  
Elham Ahmadian ◽  
Solmaz Maleki Dizaj ◽  
Aziz Eftekhari ◽  
Elaheh Dalir ◽  
Parviz Vahedi ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Biomedical Applications ◽  
Wound Repair ◽  
Stem Cell Differentiation ◽  
Clinical Applications ◽  
Cellular Behavior ◽  
Hydrogel Formation ◽  
Potential Applications ◽  
Basic Concepts ◽  
Elastic Sheets

AbstractHyaluronic acid (HA) is widely used in the biomedicine due to its biocompatibility, biodegradability, and nontoxic properties. It is crucial for cell signaling role during morphogenesis, inflammation, and wound repair. After hydrogel formation, HA easily is converted to elastic sheets in order to use in preclinical and clinical applications. In addition, HA-derived hydrogels are easily used as vectors for cell and medication in tissue repairing and regenerative medicine. Moreover, in comparison with other polymers, HA -based hydrogels play a key role in in cellular behavior, including stem cell differentiation. The current paper reviews both basic concepts and recent advances in the development of HA-based hydrogels for biomedical applications.

scholarly journals Phenol–Hyaluronic Acid Conjugates: Correlation of Oxidative Crosslinking Pathway and Adhesiveness

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3130
Author(s):  
Jungwoo Kim ◽  
Sumin Kim ◽  
Donghee Son ◽  
Mikyung Shin
Keyword(s):  
Hyaluronic Acid ◽  
Biomedical Applications ◽  
Stability Limit ◽  
Polymeric Chain ◽  
Covalent Bonds ◽  
Adhesion Properties ◽  
Covalent Crosslinking ◽  
Natural Polysaccharide ◽  
Chemical Oxidants

Hyaluronic acid (HA) is a natural polysaccharide with great biocompatibility for a variety of biomedical applications, such as tissue scaffolds, dermal fillers, and drug-delivery carriers. Despite the medical impact of HA, its poor adhesiveness and short-term in vivo stability limit its therapeutic efficacy. To overcome these shortcomings, a versatile modification strategy for the HA backbone has been developed. This strategy involves tethering phenol moieties on HA to provide both robust adhesiveness and intermolecular cohesion and can be used for oxidative crosslinking of the polymeric chain. However, a lack of knowledge still exists regarding the interchangeable phenolic adhesion and cohesion depending on the type of oxidizing agent used. Here, we reveal the correlation between phenolic adhesion and cohesion upon gelation of two different HA–phenol conjugates, HA–tyramine and HA–catechol, depending on the oxidant. For covalent/non-covalent crosslinking of HA, oxidizing agents, horseradish peroxidase/hydrogen peroxide, chemical oxidants (e.g., base, sodium periodate), and metal ions, were utilized. As a result, HA–catechol showed stronger adhesion properties, whereas HA–tyramine showed higher cohesion properties. In addition, covalent bonds allowed better adhesion compared to that of non-covalent bonds. Our findings are promising for designing adhesive and mechanically robust biomaterials based on phenol chemistry.

scholarly journals Investigation of Changes in Saliva in Radiotherapy-Induced Head Neck Cancer Patients

2021 ◽  
Vol 18 (4) ◽  
pp. 1629
Author(s):  
Christina Winter ◽  
Roman Keimel ◽  
Markus Gugatschka ◽  
Dagmar Kolb ◽  
Gerd Leitinger ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Salivary Glands ◽  
Treatment Options ◽  
Chemical Properties ◽  
Head Neck Cancer ◽  
Potential Candidate ◽  
Adhesive Properties ◽  
Whole Saliva ◽  
Radiation Induced ◽  
Unstimulated Whole Saliva

The intact function of the salivary glands is of utmost importance for oral health. During radiotherapy in patients with head and neck tumors, the salivary glands can be damaged, causing the composition of saliva to change. This leads to xerostomia, which is a primary contributor to oral mucositis. Medications used for protective or palliative treatment often show poor efficacy as radiation-induced changes in the physico-chemical properties of saliva are not well understood. To improve treatment options, this study aimed to carefully examine unstimulated whole saliva of patients receiving radiation therapy and compare it with healthy unstimulated whole saliva. To this end, the pH, osmolality, electrical conductivity, buffer capacity, the whole protein and mucin concentrations, and the viscoelastic and adhesive properties were investigated. Moreover, hyaluronic acid was examined as a potential candidate for a saliva replacement fluid. The results showed that the pH of radiation-induced saliva shifted from neutral to acidic, the osmolality increased and the viscoelastic properties changed due to a disruption of the mucin network and a change in water secretion from the salivary glands. By adopting an aqueous 0.25% hyaluronic acid formulation regarding the lost properties, similar adhesion characteristics as in healthy, unstimulated saliva could be achieved.

scholarly journals GAKTpore: Stereological Characterisation Methods for Porous Foams in Biomedical Applications

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1269
Author(s):  
Gareth Sheppard ◽  
Karl Tassenberg ◽  
Bogdan Nenchev ◽  
Joel Strickland ◽  
Ramy Mesalam ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Biomedical Applications ◽  
Large Scale ◽  
Collagen Scaffold ◽  
Porous Structures ◽  
Tissue Engineering Scaffolds ◽  
Biological Responses ◽  
Sem Micrograph ◽  
Cell Adhesion And Proliferation ◽  
Characterisation Methods

In tissue engineering, scaffolds are a key component that possess a highly elaborate pore structure. Careful characterisation of such porous structures enables the prediction of a variety of large-scale biological responses. In this work, a rapid, efficient, and accurate methodology for 2D bulk porous structure analysis is proposed. The algorithm, “GAKTpore”, creates a morphology map allowing quantification and visualisation of spatial feature variation. The software achieves 99.6% and 99.1% mean accuracy for pore diameter and shape factor identification, respectively. There are two main algorithm novelties within this work: (1) feature-dependant homogeneity map; (2) a new waviness function providing insights into the convexity/concavity of pores, important for understanding the influence on cell adhesion and proliferation. The algorithm is applied to foam structures, providing a full characterisation of a 10 mm diameter SEM micrograph (14,784 × 14,915 px) with 190,249 pores in ~9 min and has elucidated new insights into collagen scaffold formation by relating microstructural formation to the bulk formation environment. This novel porosity characterisation algorithm demonstrates its versatility, where accuracy, repeatability, and time are paramount. Thus, GAKTpore offers enormous potential to optimise and enhance scaffolds within tissue engineering.

scholarly journals 3D-printing on textiles – an investigation on adhesion properties of the produced composite materials

2021 ◽  
Vol 28 (6) ◽  
Author(s):  
Maryna Gorlachova ◽  
Boris Mahltig
Keyword(s):  
3D Printing ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Practical Applications ◽  
3D Print ◽  
3D Objects ◽  
Textile Fabrics ◽  
Polylactide Acid ◽  
Polyamide 6.6 ◽  
Textile Sector

AbstractThe actual paper is related to adhesive properties of 3D objects printed on cotton textile fabrics. For practical applications of 3D prints in the textile sector, the adhesion of the printed object on the textile substrate is an important issue. In the current study, two different types of polymers are printed on cotton – polylactide acid (PLA) and polyamide 6.6 (Nylon). Altogether six cotton fabrics differing in structure, weight and thickness are evaluated. Also, the effect of washing and enzymatic desizing is investigated. For printing parameters, best results are gained for elevated process temperatures, intermediate printing speed and low Z-distance between printing head and substrate. Also, a textile treatment by washing and desizing can improve the adhesion of an afterwards applied 3D print. The presented results are quite useful for future developments of 3D printing applications on textile substrates, e.g. to implement new decorative features or protective functions.

scholarly journals Synthesis and Evaluation of AlgNa-g-poly(QCL-co-HEMA) Hydrogels as Platform for Chondrocyte Proliferation and Controlled Release of Betamethasone

2021 ◽  
Vol 22 (11) ◽  
pp. 5730
Author(s):  
Jomarien García-Couce ◽  
Marioly Vernhes ◽  
Nancy Bada ◽  
Lissette Agüero ◽  
Oscar Valdés ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Controlled Release ◽  
Biomedical Applications ◽  
Release Kinetics ◽  
Cell Types ◽  
Tissue Engineering Scaffolds ◽  
Almost All ◽  
Scanning Electron

Hydrogels obtained from combining different polymers are an interesting strategy for developing controlled release system platforms and tissue engineering scaffolds. In this study, the applicability of sodium alginate-g-(QCL-co-HEMA) hydrogels for these biomedical applications was evaluated. Hydrogels were synthesized by free-radical polymerization using a different concentration of the components. The hydrogels were characterized by Fourier transform-infrared spectroscopy, scanning electron microscopy, and a swelling degree. Betamethasone release as well as the in vitro cytocompatibility with chondrocytes and fibroblast cells were also evaluated. Scanning electron microscopy confirmed the porous surface morphology of the hydrogels in all cases. The swelling percent was determined at a different pH and was observed to be pH-sensitive. The controlled release behavior of betamethasone from the matrices was investigated in PBS media (pH = 7.4) and the drug was released in a controlled manner for up to 8 h. Human chondrocytes and fibroblasts were cultured on the hydrogels. The MTS assay showed that almost all hydrogels are cytocompatibles and an increase of proliferation in both cell types after one week of incubation was observed by the Live/Dead® assay. These results demonstrate that these hydrogels are attractive materials for pharmaceutical and biomedical applications due to their characteristics, their release kinetics, and biocompatibility.

scholarly journals Techno-Economic Analysis of a Hyaluronic Acid Production Process Utilizing Streptococcal Fermentation

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 241
Author(s):  
Rafael G. Ferreira ◽  
Adriano R. Azzoni ◽  
Maria Helena Andrade Santana ◽  
Demetri Petrides
Keyword(s):  
Hyaluronic Acid ◽  
Economic Analysis ◽  
Lower Cost ◽  
Value Added ◽  
Production Costs ◽  
Selling Price ◽  
Baseline Scenario ◽  
Adhesive Properties ◽  
Fed Batch Culture ◽  
Economic Analyses

Hyaluronic acid (HA) is a polysaccharide of alternating d-glucuronic acid and N-acetyl-d-glucosamine residues present in the extracellular matrix of connective, epithelial, and nervous tissues. Due to its singular hydrating, rheological and adhesive properties, HA has found numerous cosmetic and medical applications. However, techno-economic analyses of high value-added bioproducts such as HA are scarce in the literature. Here, we present a techno-economic analysis of a process for producing HA using Streptococcus zooepidemicus, simulated in SuperPro Designer. In the baseline scenario, HA is produced by batch fermentation, reaching 2.5 g/L after 24 h. It is then centrifuged, diafiltered, treated with activated carbon and precipitated with isopropanol. The product is suitable for topical formulations and its production cost was estimated as 1115 $/kg. A similar scenario, based on fed-batch culture and assuming a titer of 5.0 g/L, led to a lower cost of 946 $/kg. Moreover, in two additional scenarios, 10% of the precipitated HA is diverted to the production of a highly pure and high-molecular weight HA, suitable for injectable applications. These scenarios resulted in higher capital and operating costs, but also in higher profits, because HA for injectable use has a higher selling price that more than compensates for its higher production costs.

scholarly journals Experimental and Numerical Peeling Investigation on Aged Multi-Layer Anti-Shatter Safety Films (ASFs) for Structural Glass Retrofit

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 162
Author(s):  
Silvana Mattei ◽  
Luca Cozzarini ◽  
Chiara Bedon
Keyword(s):  
Young Modulus ◽  
Adhesive Layer ◽  
Experimental Program ◽  
Fe Model ◽  
Structural Glass ◽  
Adhesive Properties ◽  
Test Protocol ◽  
Adhesion Properties ◽  
The Impact ◽  
Pet Films

Anti-shatter safety films (ASFs) are often used for structural glass applications. The goal is to improve the response of monolithic elements and prevent fragments from shattering. Thus, the main reason behind their use is the possibility to upgrade safety levels against the brittle failure of glass and minimize the number of possible injuries. However, the impact response of glass elements bonded with Polyethylene terephthalate (PET)-films and pressure sensitive adhesives (PSAs) still represents a research topic of open discussion. Major challenges derive from material characterization and asymmetrical variability under design loads and ageing. In particular, the measurement of interface mechanical characteristics for the adhesive layer in contact with glass is a primary parameter for the ASF choice optimization. For this reason, the present paper presents an experimental campaign aimed at calibrating some basic mechanical parameters that provide the characterization of constitutive models, such as tensile properties (yielding stress and Young modulus) for PET-film and adhesive properties for PSA (energy fracture and peel force). In doing so, both tensile tests for PET-films and peeling specimens are taken into account for a commercially available ASF, given that the peeling test protocol is one of most common methods for the definition of adhesion properties. Moreover, an extensive calibration of the Finite Element (FE) model is performed in order to conduct a parametric numerical analysis of ASF bonded glass solutions. Furthermore, a Kinloch approach typically used to determine the fracture energy of a given tape by considering a variable peel angle, is also adopted to compare the outcomes of calibration analyses and FE investigations on the tested specimens. Finally, a study of the effect of multiple aspects is also presented. The results of the experimental program and the following considerations confirm the rate dependence and ageing dependence in peel tests.

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