Improving Fibrin Hydrogels’ Mechanical Properties, through Addition of Silica or Chitosan-Silica Materials, for Potential Application as Wound Dressings

Fibrin is a protein-based hydrogel formed during blood coagulation. It can also be produced in vitro from human blood plasma, and it is capable of resisting high deformations. However, after each deformation process, it loses high amounts of water, which subsequently makes it mechanically unstable and, finally, difficult to manipulate. The objective of this work was to overcome the in vitro fibrin mechanical instability. The strategy consists of adding silica or chitosan-silica materials and comparing how the different materials electrokinetic-surface properties affect the achieved improvement. The siliceous materials electrostatic and steric stabilization mechanisms, together with plasma protein adsorption on their surfaces, were corroborated by DLS and ζ-potential measurements before fibrin gelling. These properties avoid phase separation, favoring homogeneous incorporation of the solid into the forming fibrin network. Young’s modulus of modified fibrin hydrogels was evaluated by AFM to quantitatively measure stiffness. It increased 2.5 times with the addition of 4 mg/mL silica. A similar improvement was achieved with only 0.7 mg/mL chitosan-silica, which highlighted the contribution of hydrophilic chitosan chains to fibrinogen crosslinking. Moreover, these chains avoided the fibroblast growth inhibition onto modified fibrin hydrogels 3D culture observed with silica. In conclusion, 0.7 mg/mL chitosan-silica improved the mechanical stability of fibrin hydrogels with low risks of cytotoxicity. This easy-to-manipulate modified fibrin hydrogel makes it suitable as a wound dressing biomaterial.

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Antimicrobial dressing of silver sulfadiazine-loaded halloysite/cassava starch-based (bio)nanocomposites

Journal of Biomaterials Applications ◽

10.1177/0885328221995920 ◽

2021 ◽

pp. 088532822199592

Author(s):

Graziele Louize Policarpio da Silva ◽

Laís Caroline de Assunção Morais ◽

Juliana Bonametti Olivato ◽

Juliano Marini ◽

Priscileila Colerato Ferrari

Keyword(s):

Zeta Potential ◽

Mechanical Stability ◽

Thermoplastic Starch ◽

Halloysite Nanotubes ◽

Cassava Starch ◽

Silver Sulfadiazine ◽

Wound Dressings ◽

Vapor Permeability

(Bio)nanocomposites have been studied for biomedical applications, including the treatment of wounds. However, wound infection is one of the main problems of wound care management, and the use of wound dressings with antibacterial agents is essential. This work focused on developing and characterizing silver sulfadiazine-loaded halloysite/cassava starch-based (bio)nanocomposites potentially suitable as antimicrobial dressing. Silver sulfadiazine was complexed inside the halloysite nanotubes lumen, and the drug-loaded nanotubes were incorporated in thermoplastic starch dispersion, forming the (bio)nanocomposites. The silver sulfadiazine-loaded halloysite and the (bio)nanocomposite were characterized by zeta potential, scanning electron microscopy, X-ray diffraction, and infrared spectroscopy. The dressing properties of (bio)nanocomposites (water vapor permeability and mechanical stability) and their antimicrobial efficacy by Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were also evaluated. Physicochemical studies suggested the silver sulfadiazine-loaded halloysite complexation (zeta potential of −38.9 mV) and its interactions with the starch forming the nanocomposites. The silver sulfadiazine-loaded halloysite/starch-based (bio)nanocomposites possessed a homogeneous and organized structure. Also, they had mechanical properties to be used as a dressing (13.73 ± 3.09 MPa and 3.17 ± 1.28% of elongation at break), and its permeability (6.18 ± 0.43 (10−13) g.Pa−1.s−1.m−1) could be able to maintain the environmental moisture at the wound surface. Besides that, the (bio)nanocomposites acted against the studied bacteria, being a potential contact antimicrobial and biodegradable wound dressing. Finally, the developed (bio)nanocomposites are semi-occlusive and good candidates for dry wounds to be widely in vitro and in vivo tested as controlled silver sulfadiazine delivery dressing.

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Preparation, characterization and in vitro wound healing activity of collagen-chitosan film

International Journal of Research in Pharmaceutical Sciences ◽

10.26452/ijrps.v11i4.3182 ◽

2020 ◽

Vol 11 (4) ◽

pp. 5489-5495

Author(s):

Ragini B ◽

Shree Rama M ◽

Shaukat Ali S R ◽

Siva S

Keyword(s):

Wound Dressing ◽

Chronic Wounds ◽

Mechanical Stability ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Chitosan Film ◽

Wound Dressings ◽

Catla Catla ◽

Chitosan Films

A rise in the incidence of skin burns and chronic wounds present a first health care problem. Hence collagen – chitosan-based wound dressing has been seen as a way to heal wounds without leaving a scar. Collagen is the most ubiquitous protein found in marine organisms. Here, chitosan plays a vital role in improving the stability of the collagen. The Collagen-chitosan films comprised of collagen derived from skins of Catla catla which were pretreated and lyophilized and confirmed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Thus, in this new approach collagen has been hybridized with the naturally occurring bioactive material chitosan to improve the mechanical properties with enhanced stability, and it can be effectively utilized for the wound dressing in clinical application. Physico-chemical properties and surface morphology of the films were analyzed through SEM and FTIR. Mechanical stability of collagen – chitosan film showed increased tensile strength and elongation at break. The Anti-bacterial and Anti-inflammatory activity of collagen - chitosan films were performed. Also, the in vitro biocompatibility of collagen chitosan films was confirmed by wound scratch assay on fibroblast cells. It was concluded that this present study reveals that the preparation of collagen-chitosan films from a new source of natural collagen could be suitable for the application of wound dressings.

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Use of 3D culture systems to generate human induced pluripotent stem cell-derived [beta]-cells in vitro

Endocrine Abstracts ◽

10.1530/endoabs.57.003 ◽

2018 ◽

Author(s):

Fantuzzi Federica ◽

Toivonen Sanna ◽

Schiavo Andrea Alex ◽

Pachera Nathalie ◽

Rajaei Bahareh ◽

...

Keyword(s):

Stem Cell ◽

Beta Cells ◽

Pluripotent Stem Cell ◽

3D Culture ◽

Induced Pluripotent Stem Cell ◽

Culture Systems ◽

Induced Pluripotent

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3D Culture Modelling: An Emerging Approach for Translational Cancer Research in Sarcomas

Current Medicinal Chemistry ◽

10.2174/0929867326666191212162102 ◽

2020 ◽

Vol 27 (29) ◽

pp. 4778-4788 ◽

Cited By ~ 1

Author(s):

Victoria Heredia-Soto ◽

Andrés Redondo ◽

José Juan Pozo Kreilinger ◽

Virginia Martínez-Marín ◽

Alberto Berjón ◽

...

Keyword(s):

High Throughput Screening ◽

Cancer Biology ◽

Soft Tissues ◽

Three Dimensional ◽

3D Culture ◽

Resistance Mechanisms ◽

In Vitro Models ◽

Tumour Spheroids ◽

Current Therapies

Sarcomas are tumours of mesenchymal origin, which can arise in bone or soft tissues. They are rare but frequently quite aggressive and with a poor outcome. New approaches are needed to characterise these tumours and their resistance mechanisms to current therapies, responsible for tumour recurrence and treatment failure. This review is focused on the potential of three-dimensional (3D) in vitro models, including multicellular tumour spheroids (MCTS) and organoids, and the latest data about their utility for the study on important properties for tumour development. The use of spheroids as a particularly valuable alternative for compound high throughput screening (HTS) in different areas of cancer biology is also discussed, which enables the identification of new therapeutic opportunities in commonly resistant tumours.

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Polymer/Iron-Based Layered Double Hydroxides as Multifunctional Wound Dressings

Pharmaceutics ◽

10.3390/pharmaceutics12111130 ◽

2020 ◽

Vol 12 (11) ◽

pp. 1130

Author(s):

Mariana Pires Figueiredo ◽

Ana Borrego-Sánchez ◽

Fátima García-Villén ◽

Dalila Miele ◽

Silvia Rossi ◽

...

Keyword(s):

Drug Release ◽

High Performance ◽

Mechanical Performance ◽

Release Kinetics ◽

Wound Dressings ◽

In Vitro Drug Release ◽

Improved Performance ◽

Double Hydroxide ◽

Double Hydroxides

This work presents the development of multifunctional therapeutic membranes based on a high-performance block copolymer scaffold formed by polyether (PE) and polyamide (PA) units (known as PEBA) and layered double hydroxide (LDH) biomaterials, with the aim to study their uses as wound dressings. Two LDH layer compositions were employed containing Mg2+ or Zn2+, Fe3+ and Al3+ cations, intercalated with chloride anions, abbreviated as Mg-Cl or Zn-Cl, or intercalated with naproxenate (NAP) anions, abbreviated as Mg-NAP or Zn-NAP. Membranes were structurally and physically characterized, and the in vitro drug release kinetics and cytotoxicity assessed. PEBA-loading NaNAP salt particles were also prepared for comparison. Intercalated NAP anions improved LDH–polymer interaction, resulting in membranes with greater mechanical performance compared to the polymer only or to the membranes containing the Cl-LDHs. Drug release (in saline solution) was sustained for at least 8 h for all samples and release kinetics could be modulated: a slower, an intermediate and a faster NAP release were observed from membranes containing Zn-NAP, NaNAP and Mg-NAP particles, respectively. In general, cell viability was higher in the presence of Mg-LDH and the membranes presented improved performance in comparison with the powdered samples. PEBA containing Mg-NAP sample stood out among all membranes in all the evaluated aspects, thus being considered a great candidate for application as multifunctional therapeutic dressings.

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Mechanical Stability of Hybrid Corrugated Sandwich Plates under Fluid-Structure-Thermal Coupling for Novel Thermal Protection Systems

Applied Sciences ◽

10.3390/app10082790 ◽

2020 ◽

Vol 10 (8) ◽

pp. 2790

Author(s):

Wenzheng Zhuang ◽

Chao Yang ◽

Zhigang Wu

Keyword(s):

Mechanical Stability ◽

Thermal Protection ◽

Element Model ◽

Parameter Study ◽

The Novel ◽

Thermal Coupling ◽

Mechanical Instability ◽

Fluid Structure ◽

Thermal Protection Systems ◽

Protection Systems

Hybrid corrugated sandwich (HCS) plates have become a promising candidate for novel thermal protection systems (TPS) due to their multi-functionality of load bearing and thermal protection. For hypersonic vehicles, the novel TPS that performs some structural functions is a potential method of saving weight, which is significant in reducing expensive design/manufacture cost. Considering the novel TPS exposed to severe thermal and aerodynamic environments, the mechanical stability of the HCS plates under fluid-structure-thermal coupling is crucial for preliminary design of the TPS. In this paper, an innovative layerwise finite element model of the HCS plates is presented, and coupled fluid-structure-thermal analysis is performed with a parameter study. The proposed method is validated to be accurate and efficient against commercial software simulation. Results have shown that the mechanical instability of the HCS plates can be induced by fluid-structure coupling and further accelerated by thermal effect. The influences of geometric parameters on thermal buckling and dynamic stability present opposite tendencies, indicating a tradeoff is required for the TPS design. The present analytical model and numerical results provide design guidance in the practical application of the novel TPS.

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Hemostatic wound dressings: Predicting their effects by in vitro tests

Journal of Biomaterials Applications ◽

10.1177/0885328219831095 ◽

2019 ◽

Vol 33 (9) ◽

pp. 1285-1297 ◽

Cited By ~ 2

Author(s):

Cornelia Wiegand ◽

Martin Abel ◽

Uta-Christina Hipler ◽

Peter Elsner ◽

Michael Zieger ◽

...

Keyword(s):

Blood Clot ◽

Wound Dressings ◽

In Vitro Tests ◽

Regenerated Cellulose ◽

Oxidized Regenerated Cellulose ◽

Inflammatory Reactions ◽

In Vitro Techniques ◽

Cotton Gauze

Background Application of controlled in vitro techniques can be used as a screening tool for the development of new hemostatic agents allowing quantitative assessment of overall hemostatic potential. Materials and methods Several tests were selected to evaluate the efficacy of cotton gauze, collagen, and oxidized regenerated cellulose for enhancing blood clotting, coagulation, and platelet activation. Results Visual inspection of dressings after blood contact proved the formation of blood clots. Scanning electron microscopy demonstrated the adsorption of blood cells and plasma proteins. Significantly enhanced blood clot formation was observed for collagen together with β-thromboglobulin increase and platelet count reduction. Oxidized regenerated cellulose demonstrated slower clotting rates not yielding any thrombin generation; yet, led to significantly increased thrombin-anti-thrombin-III complex levels compared to the other dressings. As hemostyptica ought to function without triggering any adverse events, induction of hemolysis, instigation of inflammatory reactions, and initiation of the innate complement system were also tested. Here, cotton gauze provoked high PMN elastase and elevated SC5b-9 concentrations. Conclusions A range of tests for desired and undesired effects of materials need to be combined to gain some degree of predictability of the in vivo situation. Collagen-based dressings demonstrated the highest hemostyptic properties with lowest adverse reactions whereas gauze did not induce high coagulation activation but rather activated leukocytes and complement.

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Plectin ensures intestinal epithelial integrity and protects colon against colitis

Mucosal Immunology ◽

10.1038/s41385-021-00380-z ◽

2021 ◽

Vol 14 (3) ◽

pp. 691-702

Author(s):

Alzbeta Krausova ◽

Petra Buresova ◽

Lenka Sarnova ◽

Gizem Oyman-Eyrilmez ◽

Jozef Skarda ◽

...

Keyword(s):

Mechanical Stability ◽

Intestinal Barrier ◽

Intercellular Junctions ◽

Protein Profiling ◽

Cell Junctions ◽

Intestinal Barrier Function ◽

Intestinal Epithelial ◽

Critical Determinant ◽

In Vitro Feeding

AbstractPlectin, a highly versatile cytolinker protein, provides tissues with mechanical stability through the integration of intermediate filaments (IFs) with cell junctions. Here, we hypothesize that plectin-controlled cytoarchitecture is a critical determinant of the intestinal barrier function and homeostasis. Mice lacking plectin in an intestinal epithelial cell (IEC; PleΔIEC) spontaneously developed colitis characterized by extensive detachment of IECs from the basement membrane (BM), increased intestinal permeability, and inflammatory lesions. Moreover, plectin expression was reduced in the colons of ulcerative colitis (UC) patients and negatively correlated with the severity of colitis. Mechanistically, plectin deficiency in IECs led to aberrant keratin filament (KF) network organization and the formation of dysfunctional hemidesmosomes (HDs) and intercellular junctions. In addition, the hemidesmosomal α6β4 integrin (Itg) receptor showed attenuated association with KFs, and protein profiling revealed prominent downregulation of junctional constituents. Consistent with the effects of plectin loss in the intestinal epithelium, plectin-deficient IECs exhibited remarkably reduced mechanical stability and limited adhesion capacity in vitro. Feeding mice with a low-residue liquid diet that reduced mechanical stress and antibiotic treatment successfully mitigated epithelial damage in the PleΔIEC colon.

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In vitro effects of temperature on red blood cell deformability and membrane stability in human and various vertebrate species

Clinical Hemorheology and Microcirculation ◽

10.3233/ch-211118 ◽

2021 ◽

pp. 1-10

Author(s):

Adam Attila Matrai ◽

Gabor Varga ◽

Bence Tanczos ◽

Barbara Barath ◽

Adam Varga ◽

...

Keyword(s):

Blood Cell ◽

Red Blood Cell ◽

Whole Blood ◽

Mechanical Stability ◽

Cell Deformability ◽

Blood Samples ◽

Effects Of Temperature ◽

The Way ◽

Rbc Deformability

BACKGROUND: The effects of temperature on micro-rheological variables have not been completely revealed yet. OBJECTIVE: To investigate micro-rheological effects of heat treatment in human, rat, dog, and porcine blood samples. METHODS: Red blood cell (RBC) - buffer suspensions were prepared and immersed in a 37, 40, and 43°C heat-controlled water bath for 10 minutes. Deformability, as well as mechanical stability of RBCs were measured in ektacytometer. These tests were also examined in whole blood samples at various temperatures, gradually between 37 and 45°C in the ektacytometer. RESULTS: RBC deformability significantly worsened in the samples treated at 40 and 43°C degrees, more expressed in human, porcine, rat, and in smaller degree in canine samples. The way of heating (incubation vs. ektacytometer temperation) and the composition of the sample (RBC-PBS suspension or whole blood) resulted in the different magnitude of RBC deformability deterioration. Heating affected RBC membrane (mechanical) stability, showing controversial alterations. CONCLUSION: Significant changes occur in RBC deformability by increasing temperature, showing inter-species differences. The magnitude of alterations is depending on the way of heating and the composition of the sample. The results may contribute to better understanding the micro-rheological deterioration in hyperthermia or fever.

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Development of Spanish Broom and Flax Dressings with Glycyrrhetinic Acid-Loaded Films for Wound Healing: Characterization and Evaluation of Biological Properties

Pharmaceutics ◽

10.3390/pharmaceutics13081192 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1192

Author(s):

Angela Abruzzo ◽

Concettina Cappadone ◽

Valentina Sallustio ◽

Giovanna Picone ◽

Martina Rossi ◽

...

Keyword(s):

Wound Healing ◽

Drug Loading ◽

Healing Process ◽

In Vitro Release ◽

Sodium Hyaluronate ◽

Biological Properties ◽

Glycyrrhetinic Acid ◽

Wound Dressings ◽

Biological Studies

The selection of an appropriate dressing for each type of wound is a very important procedure for a faster and more accurate healing process. So, the aim of this study was to develop innovative Spanish Broom and flax wound dressings, as alternatives to cotton used as control, with polymeric films containing glycyrrhetinic acid (GA) to promote wound-exudate absorption and the healing process. The different wound dressings were prepared by a solvent casting method, and characterized in terms of drug loading, water uptake, and in vitro release. Moreover, biological studies were performed to evaluate their biocompatibility and wound-healing efficacy. Comparing the developed wound dressings, Spanish Broom dressings with GA-loaded sodium hyaluronate film had the best functional properties, in terms of hydration ability and GA release. Moreover, they showed a good biocompatibility, determining a moderate induction of cell proliferation and no cytotoxicity. In addition, the wound-healing test revealed that the Spanish Broom dressings promoted cell migration, further facilitating the closure of the wound.

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