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1.
Cells Tissues Organs ; 212(3): 258-271, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35158354

RESUMO

The production of a cellularized silk fibroin scaffold is very difficult because it is actually impossible to differentiate cells into a well-organized cardiac tissue. Without vascularization, not only do cell masses fail to grow, but they may also exhibit an area of necrosis, indicating a lack of oxygen and nutrients. In the present study, we used the so-called tyrosine protein kinase kit (c-Kit)-positive cardiac progenitor cells (CPCs) to generate cardiac cellularized silk fibroin scaffolds, multipotent cells isolated from the adult heart to date that can show some degree of differentiation toward the cardiac phenotype. To test their ability to differentiate into the cardiac phenotype in vivo as well, CPC and collagen organoid-like masses were implanted into nude mice and their behavior observed. Since the 3-dimensional structure of cardiac tissue can be preserved by scaffolds, we prepared in parallel different silk fibroin scaffolds with 3 different geometries and tested their behavior in 3 different models of immunosuppressed animals. Unfortunately, CPC cellularized silk fibroin scaffolds cannot be used in vivo. CPCs implanted alone or in collagen type I gel were destroyed by CD3+ lymphocyte aggregates, whereas the porous and partially oriented scaffolds elicited a consistent foreign body response characterized by giant cells. Only the electrospun meshes were resistant to the foreign body reaction. In conclusion, c-Kit-positive CPCs, although expressing a good level of cardiac differentiation markers in vitro with or without fibroin meshes, are not suitable for an in vivo model of cardiac organoids because they are degraded by a T-cell-mediated immune response. Even scaffolds which may preserve the survival of these cells in vivo also induced a host response. However, among the tested scaffolds, the electrospun meshes (F-scaffold) induced a lower response compared to all the other tested structures.


Assuntos
Fibroínas , Camundongos , Animais , Fibroínas/química , Seda/química , Alicerces Teciduais/química , Engenharia Tecidual/métodos , Camundongos Nus , Células-Tronco/metabolismo
2.
Surg Endosc ; 36(12): 8797-8806, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35578046

RESUMO

BACKGROUND: Recently, in the field of abdominal wall repair surgery, some minimally invasive procedures introduced the use of staplers to provide a retromuscular prosthetic repair. However, to the knowledge of the authors, there are little data in the literature about the outcomes of stapled sutures adoption for midline reconstruction. This study aims to investigate the biomechanics of stapled sutures, simple (stapled), or oversewn (hybrid), in comparison with handsewn suture. From the results obtained, we tried to draw indications for their use in a clinical context. METHODS: Human cadaver fascia lata specimens, sutured (handsewn, stapled, or hybrid) or not, underwent tensile tests. The data on strength (maximal stress), ultimate strain (deformability), Young's modulus (rigidity), and dissipated specific energy (ability to absorb mechanical energy up to the breaking point) were recorded for each type of specimens and analyzed. RESULTS: Stapled and hybrid suture showed a significantly higher strength (handsewn 0.83 MPa, stapled 2.10 MPa, hybrid 2.68 MPa) and a trend toward a lower ultimate strain as compared to manual sutures (handsewn 344%, stapled 249%, hybrid 280%). Stapled and hybrid sutures had fourfold higher Young's modulus as compared to handsewn sutures (handsewn 1.779 MPa, stapled 7.374 MPa, hybrid 6.964 MPa). Handsewn and hybrid sutures showed significantly higher dissipated specific energy (handsewn 0.99 mJ-mm3, stapled 0.73 mJ-mm3, hybrid 1.35 mJ-mm3). CONCLUSION: Stapled sutures can resist high loads, but are less deformable and rigid than handsewn suture. This suggests a safer employment in case of small defects or diastasis (< W1 in accord to EHS classification), where the presumed tissutal displacement is minimal. Oversewing a stapled suture improves its efficiency, becoming crucial in case of larger defects (> W1 in accord to EHS classification) where the expected tissutal displacement is maximal. Hybrid sutures seem to be a good compromise.


Assuntos
Proctocolectomia Restauradora , Grampeamento Cirúrgico , Humanos , Técnicas de Sutura , Suturas , Proctocolectomia Restauradora/métodos , Anastomose Cirúrgica/métodos
3.
Prog Polym Sci ; 1152021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33776158

RESUMO

Three-dimensional (3D) printing is a transformative manufacturing strategy, allowing rapid prototyping, customization, and flexible manipulation of structure-property relationships. Proteins are particularly appealing to formulate inks for 3D printing as they serve as essential structural components of living systems, provide a support presence in and around cells and for tissue functions, and also provide the basis for many essential ex vivo secreted structures in nature. Protein-based inks are beneficial in vivo due to their mechanics, chemical and physical match to the specific tissue, and full degradability, while also to promoting implant-host integration and serving as an interface between technology and biology. Exploiting the biological, chemical, and physical features of protein-based inks can provide key opportunities to meet the needs of tissue engineering and regenerative medicine. Despite these benefits, protein-based inks impose nontrivial challenges to 3D printing such as concentration and rheological features and reconstitution of the structural hierarchy observed in nature that is a source of the robust mechanics and functions of these materials. This review introduces photo-crosslinking mechanisms and rheological principles that underpins a variety of 3D printing techniques. The review also highlights recent advances in the design, development, and biomedical utility of monolithic and composite inks from a range of proteins, including collagen, silk, fibrinogen, and others. One particular focus throughout the review is to introduce unique material characteristics of proteins, including amino acid sequences, molecular assembly, and secondary conformations, which are useful for designing printing inks and for controlling the printed structures. Future perspectives of 3D printing with protein-based inks are also provided to support the promising spectrum of biomedical research accessible to these materials.

4.
Soft Matter ; 17(28): 6863-6872, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34227640

RESUMO

In the tissue-engineering field silk fibroin can be tailored to the target applications by modifying its secondary structure and molecular weight, and functionalizing the molecule with specific active groups linked to the amino acid side chains. To better tune the silk fibroin molecular weight and structural properties, we propose the creation of a lower molecular weight fibroin-derived material through a selective and tunable enzymatic attack on the fibroin chain. Cleavage at specific amino acid sites leads to precise silk fibroin fragmentation and, thus, lower molecular weight materials whose length and properties can be tuned with the enzyme concentration. The cleavage increased the presence of free amino groups, hence reactivity, and aqueous solutions of the resulting polymer remained stable for up to seven days. Films of fragmented fibroin were prepared and characterized, demonstrating that the fragmentation did not affect ß-sheet formation after methanol treatment, but differences were detected after the water-vapor annealing process, confirmed by structural and thermal analyses. The adopted fragmentation method is fast, controllable and precise, allowing the creation of a silk-derived material class that is stable in water, with a tunable molecular weight and secondary structure rearrangements, and is thus a versatile tool for the further tunability and modulation of bioengineered constructs.


Assuntos
Bombyx , Fibroínas , Animais , Estrutura Secundária de Proteína , Seda , Engenharia Tecidual
5.
Int J Mol Sci ; 22(24)2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34948473

RESUMO

Bone tissue engineering has developed significantly in recent years as there has been increasing demand for bone substitutes due to trauma, cancer, arthritis, and infections. The scaffolds for bone regeneration need to be mechanically stable and have a 3D architecture with interconnected pores. With the advances in additive manufacturing technology, these requirements can be fulfilled by 3D printing scaffolds with controlled geometry and porosity using a low-cost multistep process. The scaffolds, however, must also be bioactive to promote the environment for the cells to regenerate into bone tissue. To determine if a low-cost 3D printing method for bespoke SiOC(N) porous structures can regenerate bone, these structures were tested for osteointegration potential by using human mesenchymal stem cells (hMSCs). This includes checking the general biocompatibilities under the osteogenic differentiation environment (cell proliferation and metabolism). Moreover, cell morphology was observed by confocal microscopy, and gene expressions on typical osteogenic markers at different stages for bone formation were determined by real-time PCR. The results of the study showed the pore size of the scaffolds had a significant impact on differentiation. A certain range of pore size could stimulate osteogenic differentiation, thus promoting bone regrowth and regeneration.


Assuntos
Osso e Ossos/fisiologia , Cerâmica/química , Células-Tronco Mesenquimais/citologia , Silício/química , Engenharia Tecidual/métodos , Regeneração Óssea , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Humanos , Osteogênese , Porosidade , Impressão Tridimensional , Alicerces Teciduais
6.
Adv Exp Med Biol ; 1249: 39-49, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32602089

RESUMO

As one of the important branches of natural biopolymer, natural fibrous protein has a lot of advantages including good mechanical properties, excellent biocompatibility, controllable biodegradability, renewability, abundant sources, and so on. Moreover, natural fibrous protein is also a protein that could only be used for structure supporting without any bioactivities, which attracts a lot of attentions in the field of tissue engineering scaffold. This chapter is taking silk fibroin and keratin as model materials of natural fibrous protein, focusing on their protein structure, chemical compositions, processing and extraction methods, chemical modification methods, and their applications in tissue engineering through advanced manufacturing.


Assuntos
Materiais Biocompatíveis , Fibroínas , Queratinas , Engenharia Tecidual/métodos , Fibroínas/química , Humanos , Queratinas/química , Alicerces Teciduais
7.
Adv Exp Med Biol ; 1058: 3-30, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29691815

RESUMO

Materials selection is a critical aspect for the production of scaffolds for osteochondral tissue engineering. Synthetic materials are the result of man-made operations and have been investigated for a variety of tissue engineering applications. Instead, the products of physiological processes and the metabolic activity of living organisms are identified as natural materials. Over the recent decades, a number of natural materials, namely, biopolymers and bioceramics, have been proposed as the main constituent of osteochondral scaffolds, but also as cell carriers and signaling molecules. Overall, natural materials have been investigated both in the bone and in the cartilage compartment, sometimes alone, but often in combination with other biopolymers or synthetic materials. Biopolymers and bioceramics possess unique advantages over their synthetic counterparts due similarity with natural extracellular matrix, the presence of cell recognition sites and tunable chemistry. However, the characteristics of natural origin materials can vary considerably depending on the specific source and extraction process. A deeper understanding of the relationship between material variability and biological activity and the definition of standardized manufacturing procedures will be crucial for the future of natural materials in tissue engineering.


Assuntos
Biopolímeros/química , Osso e Ossos , Cartilagem , Cerâmica/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Animais , Osso e Ossos/citologia , Osso e Ossos/metabolismo , Cartilagem/citologia , Cartilagem/metabolismo , Humanos
8.
Biosci Biotechnol Biochem ; 80(2): 241-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26399155

RESUMO

Sericin was extracted from three strains of Thai Bombyx mori silk cocoons (white shell Chul1/1, greenish shell Chul3/2, and yellow shell Chul4/2) by a high-pressure and high-temperature technique. The characteristics of sericin extracted from different fractions (15, 45, and 60 min extraction process) were compared. No differences in amino acid composition were observed among the three fractions. For all silk strains, sericin extracted from a 15-min process presented the highest molecular weight. The biological potential of the different sericin samples as a bioadditive for 3T3 fibroblast cells was assessed. When comparing sericin extracted from three silk strains, sericin fractions extracted from Chul4/2 improved cell proliferation, while sericin from Chul 1/1 activated Type I collagen production to the highest extent. This study allows the natural variability of sericin obtained from different sources and extraction conditions to be addressed and provides clues for the selection of sericin sources.


Assuntos
Aminoácidos/química , Bombyx/genética , Proteínas de Insetos/química , Sericinas/química , Animais , Bombyx/metabolismo , Proliferação de Células/efeitos dos fármacos , Cromatografia de Fase Reversa , Expressão Gênica , Proteínas de Insetos/biossíntese , Proteínas de Insetos/isolamento & purificação , Proteínas de Insetos/farmacologia , Extração Líquido-Líquido/métodos , Camundongos , Peso Molecular , Células NIH 3T3 , Sericinas/biossíntese , Sericinas/isolamento & purificação , Sericinas/farmacologia , Fatores de Tempo
9.
Bioconjug Chem ; 26(8): 1571-81, 2015 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-26106949

RESUMO

Injectable hyaluronic acid (HA)-based hydrogels compose a promising class of materials for tissue engineering and regenerative medicine applications. However, their limited mechanical properties restrict the potential range of application. In this study, cellulose nanocrystals (CNCs) were employed as nanofillers in a fully biobased strategy for the production of reinforced HA nanocomposite hydrogels. Herein we report the development of a new class of injectable hydrogels composed of adipic acid dihydrazide-modified HA (ADH-HA) and aldehyde-modified HA (a-HA) reinforced with varying contents of aldehyde-modified CNCs (a-CNCs). The obtained hydrogels were characterized in terms of internal morphology, mechanical properties, swelling, and degradation behavior in the presence of hyaluronidase. Our findings suggest that the incorporation of a-CNCs in the hydrogel resulted in a more organized and compact network structure and led to stiffer hydrogels (maximum storage modulus, E', of 152.4 kPa for 0.25 wt % a-CNCs content) with improvements of E' up to 135% in comparison to unfilled hydrogels. In general, increased amounts of a-CNCs led to lower equilibrium swelling ratios and higher resistance to degradation. The biological performance of the developed nanocomposites was assessed toward human adipose derived stem cells (hASCs). HA-CNCs nanocomposite hydrogels exhibited preferential cell supportive properties in in vitro culture conditions due to higher structural integrity and potential interaction of microenvironmental cues with CNC's sulfate groups. hASCs encapsulated in HA-CNCs hydrogels demonstrated the ability to spread within the volume of gels and exhibited pronounced proliferative activity. Together, these results demonstrate that the proposed strategy is a valuable toolbox for fine-tuning the structural, biomechanical, and biochemical properties of injectable HA hydrogels, expanding their potential range of application in the biomedical field.


Assuntos
Tecido Adiposo/citologia , Celulose/química , Ácido Hialurônico/química , Hidrogéis/administração & dosagem , Células-Tronco Mesenquimais/citologia , Nanopartículas/química , Engenharia Tecidual , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Hidrogéis/química , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier
10.
Nanotechnology ; 26(12): 125102, 2015 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-25744555

RESUMO

The purpose of the current study was to develop and optimize novel self-nanoemulsifying drug delivery systems (SNEDDS) with a high proportion of essential oil as carriers for lipophilic drugs. Solubility and droplet size as a function of the composition were investigated, and a ternary phase diagram was constructed in order to identify the self-emulsification regions. The optimized SNEDDS formulation consisted of lemon essential oil (oil), Cremophor RH40 (surfactant) and Transcutol HP (co-surfactant) in the ratio 50:30:20 (v/v). Ibuprofen was chosen as the model drug. The droplet size, ζ-potential and stability of the drug-loaded optimized formulations were determined. The stability of SNEDDS was proved after triple freezing/thawing cycles and storage at 4 °C and 25 °C for 3 months. In vitro drug release studies of optimized SNEDDS revealed a significant increase of the drug release and release rate in comparison to the Ibuprofen suspension (80% versus approximately 40% in 2 h). The results indicated that these SNEDDS formulations could be used to improve the bioavailability of lipophilic drugs.


Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Sistemas de Liberação de Medicamentos/métodos , Emulsões/química , Ibuprofeno/química , Nanoestruturas/uso terapêutico , Liberação Controlada de Fármacos , Etilenoglicóis/química , Óleos Voláteis/química , Polietilenoglicóis/química
11.
Bioact Mater ; 35: 122-134, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38312518

RESUMO

The shortage of tissues and organs for transplantation is an urgent clinical concern. In situ 3D printing is an advanced 3D printing technique aimed at printing the new tissue or organ directly in the patient. The ink for this process is central to the outcomes, and must meet specific requirements such as rapid gelation, shape integrity, stability over time, and adhesion to surrounding healthy tissues. Among natural materials, silk fibroin exhibits fascinating properties that have made it widely studied in tissue engineering and regenerative medicine. However, further improvements in silk fibroin inks are needed to match the requirements for in situ 3D printing. In the present study, silk fibroin-based inks were developed for in situ applications by exploiting covalent crosslinking process consisting of a pre-photo-crosslinking prior to printing and in situ enzymatic crosslinking. Two different silk fibroin molecular weights were characterized and the synergistic effect of the covalent bonds with shear forces enhanced the shift in silk secondary structure toward ß-sheets, thus, rapid stabilization. These hydrogels exhibited good mechanical properties, stability over time, and resistance to enzymatic degradation over 14 days, with no significant changes over time in their secondary structure and swelling behavior. Additionally, adhesion to tissues in vitro was demonstrated.

12.
Biomimetics (Basel) ; 9(4)2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38667229

RESUMO

The treatment of bone defects is a clinical challenge. Bone tissue engineering is gaining interest as an alternative to current treatments, with the development of 3D porous structures (scaffolds) helpful in promoting bone regeneration by ensuring temporary functional support. In this work, methacrylated silk fibroin (SilMA) sponges were investigated as scaffolds for bone tissue engineering by exploiting the combination of physical (induced by NaCl salt during particulate leaching) and chemical crosslinking (induced by UV-light exposure) techniques. A biomimetic approach was adopted to better simulate the extracellular matrix of the bone by introducing either natural (mussel shell-derived) or synthetic-origin hydroxyapatite nanoparticles into the SilMA sponges. The obtained materials were characterized in terms of pore size, water absorption capability and mechanical properties to understand both the effect of the inclusion of the two different types of nanoparticles and the effect of the photocrosslinking. Moreover, the SilMA sponges were tested for their bioactivity and suitability for bone tissue engineering purposes by using osteosarcoma cells, studying their metabolism by an AlamarBlue assay and their morphology by scanning electron microscopy. Results indicate that photocrosslinking helps in obtaining more regular structures with bimodal pore size distributions and in enhancing the stability of the constructs in water. Moreover, the addition of naturally derived hydroxyapatite was observed to be more effective at activating osteosarcoma cell metabolism than synthetic hydroxyapatite, showing a statistically significant difference in the AlamarBlue measurement on day 7 after seeding. The methacrylated silk fibroin/hydroxyapatite nanocomposite sponges developed in this work were found to be promising tools for targeting bone regeneration with a sustainable approach.

13.
Biomater Adv ; 161: 213887, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38735199

RESUMO

Critical size bone defects cannot heal without aid and current clinical approaches exhibit some limitations, underling the need for novel solutions. Silk fibroin, derived from silkworms, is widely utilized in tissue engineering and regenerative medicine due to its remarkable properties, making it a promising candidate for bone tissue regeneration in vitro and in vivo. However, the clinical translation of silk-based materials requires refinements in 3D architecture, stability, and biomechanical properties. In earlier research, improved mechanical resistance and stability of chemically crosslinked methacrylate silk fibroin (Sil-Ma) sponges over physically crosslinked counterparts were highlighted. Furthermore, the influence of photo-initiator and surfactant concentrations on silk properties was investigated. However, the characterization of sponges with Sil-Ma solution concentrations above 10 % (w/V) was hindered by production optimization challenges, with only cell viability assessed. This study focuses on the evaluation of methacrylate sponges' suitability as temporal bone tissue regeneration scaffolds. Sil-Ma sponge fabrication at a fixed concentration of 20 % (w/V) was optimized and the impact of photo-initiator (LAP) concentrations and surfactant (Tween 80) presence/absence was studied. Their effects on pore formation, silk secondary structure, mechanical properties, and osteogenic differentiation of hBM-MSCs were investigated. We demonstrated that, by tuning silk sponges' composition, the optimal combination boosted osteogenic gene expression, offering a strategy to tailor biomechanical properties for effective bone regeneration. Utilizing Design of Experiment (DoE), correlations between sponge composition, porosity, and mechanical properties are established, guiding tailored material outcomes. Additionally, correlation matrices elucidate the microstructure's influence on gene expressions, providing insights for personalized approaches in bone tissue regeneration.


Assuntos
Regeneração Óssea , Fibroínas , Tensoativos , Engenharia Tecidual , Alicerces Teciduais , Fibroínas/química , Alicerces Teciduais/química , Tensoativos/química , Animais , Engenharia Tecidual/métodos , Regeneração Óssea/efeitos dos fármacos , Humanos , Osso e Ossos/efeitos dos fármacos , Reagentes de Ligações Cruzadas/química , Osteogênese/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Materiais Biocompatíveis/química , Porosidade
14.
Biomacromolecules ; 14(1): 38-47, 2013 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-23134349

RESUMO

In spite of commercially available products, the complete and sustained repair of damaged articular cartilage still presents various challenges. Among biomaterials proposed for cartilage repair, silk fibroin (SF) has been recently proposed as a material template for porous scaffolds cultured with chondrocytes and investigated in static and dynamic conditions. In addition to fibroin-based constructs, literature has reported that the combination of hyaluronic acid (HA) with other scaffold materials can protect the chondral phenotype and the cells in vitro response to the scaffold. In this study, the effect of the addition of HA on the physical properties of SF sponges, with and without cross-linking with genipin, was investigated. Salt-leached scaffolds were characterized in terms of morphology and structural and physical properties, as well as mechanical performance. Un-cross-linked sponges resulted in the physical separation of highly hydrophilic HA from the SF, while cross-linking prevented this phenomenon, resulting in a homogeneous blend. The presence of HA also influenced fibroin crystallinity and tended to decrease the cross-linking degree of the scaffolds when compared to the pure SF material.


Assuntos
Cartilagem Articular/química , Fibroínas/química , Ácido Hialurônico/química , Seda/química , Engenharia Tecidual/métodos , Animais , Bombyx , Fibroínas/isolamento & purificação , Porosidade , Seda/isolamento & purificação , Alicerces Teciduais/química
15.
Sci Rep ; 13(1): 15296, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37714876

RESUMO

Silk degumming is considered the first point in the preparation of silk-based materials since this process could modify the silk fiber and the properties of its related products. This study evaluated the differences in morphology, secondary structure, amino acid content, thermal stability, and mechanical properties of two types of raw materials, defective cocoons (DC) and silk fibrous waste (SW), degummed by chemical (C) and autoclaving (A) methods. Subsequently, silk fibroin films were prepared by dissolving each type of degummed fibers, and thermal and structural films properties were determined. The findings demonstrated that autoclaving is an efficient alternative to remove silk sericin, as the resulting fibers presented improved structural, thermal, and mechanical properties compared to those obtained by the chemical method. For films preparation, autoclave resulted in a good option, but dissolution parameters need to be adjusted for defective cocoons. Furthermore, similarities between the physicochemical properties of fibers and films from both fibrous wastes suggest that SW is a promising raw material for producing fibrous resources and regenerated silk fibroin materials. Overall, these findings suggest new recycling methods for fibrous waste and by-products generated in the silk textile production process.


Assuntos
Fibroínas , Seda , Filmes Cinematográficos , Têxteis , Aminoácidos
16.
Gels ; 9(11)2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37999002

RESUMO

Damages to the intervertebral disc (IVD) due to improper loading or degeneration result in back pain, which is a common disease affecting an increasing number of patients. Different strategies for IVD remediation have been developed, from surgical treatment to disc replacement, by using both metallic and non-metallic materials. Hydrogels are very attractive materials due to their ability to simulate the properties of many soft tissues; moreover, their chemical composition can be varied in order to assure performances similar to the natural disc. In particular, for the replacement of the IVD outer ring, namely, the anulus fibrosus, the shear properties are of paramount importance. In this work, we produced hydrogels through the photo-induced crosslinking of different mixtures composed of two hydrophilic monofunctional and difunctional polymers, namely, poly(ethyleneglycol) methyl ether methacrylate (PEGMEMA) and poly(ethyleneglycol) dimethacrylate (PEGDMA), together with a hydrophobic molecule, i.e., tert-butyl acrylate (tBA). By changing the ratio among the precursors, we demonstrated the tunability of both the shear properties and hydrophilicity. The structural properties of hydrogels were studied by solid-state nuclear magnetic resonance (NMR). These experiments provided insights on both the structure and molecular dynamics of polymeric networks and, together with information obtained by differential scanning calorimetry (DSC), allowed for correlating the physical properties of the hydrogels with their chemical composition.

17.
ACS Biomater Sci Eng ; 9(3): 1320-1331, 2023 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-36848685

RESUMO

Extrusion-based bioprinting is one of the most widespread technologies due to its affordability, wide range of processable materials, and ease of use. However, the formulation of new inks for this technique is based on time-consuming trial-and-error processes to establish the optimal ink composition and printing parameters. Here, a dynamic printability window was modeled for the assessment of the printability of polysaccharide blend inks of alginate and hyaluronic acid with the intent to build a versatile predictive tool to speed up the testing procedures. The model considers both the rheological properties of the blends (viscosity, shear thinning behavior, and viscoelasticity) and their printability (in terms of extrudability and the ability of forming a well-defined filament and detailed geometries). By imposing some conditions on the model equations, it was possible to define empirical bands in which the printability is ensured. The predictive capability of the built model was successfully verified on an untested blend of alginate and hyaluronic acid chosen to simultaneously optimize the printability index and minimize the size of the deposited filament.


Assuntos
Bioimpressão , Tinta , Bioimpressão/métodos , Ácido Hialurônico , Alginatos , Impressão Tridimensional
18.
J Phys Chem Lett ; 14(36): 8145-8150, 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37669464

RESUMO

The cryopreservation of cells, tissue, and organs is essential in both fundamental research and practical applications, such as modern regenerative medicine and technological applications. However, the formation of ice crystals during ice recrystallization can have harmful or even fatal effects on biological systems. To address this challenge, we explore the ice recrystallization inhibition (IRI) activity of two natural silk proteins of Bombyx mori, fibroin and sericin. We found that silk fibroin (SF) had higher ice recrystallization inhibition activity than silk sericin (SS). Moreover, SF aqueous solutions perform better in inhibiting ice recrystallization than SF phosphate-buffered saline solutions. Sum-frequency generation spectroscopy shows that stronger electrostatic interactions are responsible for the higher IRI ability of SF. This work is significant for broadening the applications of silk proteins in biomedical fields.


Assuntos
Bombyx , Fibroínas , Sericinas , Animais , Seda , Gelo
19.
Materials (Basel) ; 16(7)2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-37049037

RESUMO

Tissue engineering products have grown in popularity as a therapeutic approach for chronic wounds and burns. However, some drawbacks include additional steps and a lack of antibacterial capacities, both of which need to be addressed to treat wounds effectively. This study aimed to develop an acellular, ready-to-use ovine tendon collagen type I (OTC-I) bioscaffold with an antibacterial coating for the immediate treatment of skin wounds and to prevent infection post-implantation. Two types of crosslinkers, 0.1% genipin (GNP) and dehydrothermal treatment (DHT), were explored to optimise the material strength and biodegradability compared with a non-crosslinked (OTC) control. Carvone plasma polymerisation (ppCar) was conducted to deposit an antibacterial protective coating. Various parameters were performed to investigate the physicochemical properties, mechanical properties, microstructures, biodegradability, thermal stability, surface wettability, antibacterial activity and biocompatibility of the scaffolds on human skin cells between the different crosslinkers, with and without plasma polymerisation. GNP is a better crosslinker than DHT because it demonstrated better physicochemical properties (27.33 ± 5.69% vs. 43 ± 7.64% shrinkage), mechanical properties (0.15 ± 0.15 MPa vs. 0.07 ± 0.08 MPa), swelling (2453 ± 419.2% vs. 1535 ± 392.9%), biodegradation (0.06 ± 0.06 mg/h vs. 0.15 ± 0.16 mg/h), microstructure and biocompatibility. Similarly, its ppCar counterpart, GNPppCar, presents promising results as a biomaterial with enhanced antibacterial properties. Plasma-polymerised carvone on a crosslinked collagen scaffold could also support human skin cell proliferation and viability while preventing infection. Thus, GNPppCar has potential for the rapid treatment of healing wounds.

20.
Front Bioeng Biotechnol ; 11: 1160577, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37292094

RESUMO

Skin tissue engineering possesses great promise in providing successful wound injury and tissue loss treatments that current methods cannot treat or achieve a satisfactory clinical outcome. A major field direction is exploring bioscaffolds with multifunctional properties to enhance biological performance and expedite complex skin tissue regeneration. Multifunctional bioscaffolds are three-dimensional (3D) constructs manufactured from natural and synthetic biomaterials using cutting-edge tissue fabrication techniques incorporated with cells, growth factors, secretomes, antibacterial compounds, and bioactive molecules. It offers a physical, chemical, and biological environment with a biomimetic framework to direct cells toward higher-order tissue regeneration during wound healing. Multifunctional bioscaffolds are a promising possibility for skin regeneration because of the variety of structures they provide and the capacity to customise the chemistry of their surfaces, which allows for the regulated distribution of bioactive chemicals or cells. Meanwhile, the current gap is through advanced fabrication techniques such as computational designing, electrospinning, and 3D bioprinting to fabricate multifunctional scaffolds with long-term safety. This review stipulates the wound healing processes used by commercially available engineered skin replacements (ESS), highlighting the demand for a multifunctional, and next-generation ESS replacement as the goals and significance study in tissue engineering and regenerative medicine (TERM). This work also scrutinise the use of multifunctional bioscaffolds in wound healing applications, demonstrating successful biological performance in the in vitro and in vivo animal models. Further, we also provided a comprehensive review in requiring new viewpoints and technological innovations for the clinical application of multifunctional bioscaffolds for wound healing that have been found in the literature in the last 5 years.

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