Full synthetic 3D fibrous scaffolds for stromal tissues – replacement of animal‐derived scaffold materials demonstrated by multilayered skin

AbstractMineralized tissue regeneration is an important and challenging part of the field of tissue engineering and regeneration. At present, autograft harvest procedures may cause secondary trauma to patients, while bone scaffold materials lack osteogenic activity, resulting in a limited application. Loaded with osteogenic induction growth factor can improve the osteoinductive performance of bone graft, but the explosive release of growth factor may also cause side effects. In this study, we innovatively used platelet-rich fibrin (PRF)-modified bone scaffolds (Bio-Oss®) to replace autograft, and used cytokine (BMP-2) to enhance osteogenesis. Encouragingly, this mixture, which we named “Autograft Mimic (AGM)”, has multiple functions and advantages. (1) The fiber network provided by PRF binds the entire bone scaffold together, thereby shaping the bone grafts and maintaining the space of the defect area. (2) The sustained release of BMP-2 from bone graft promoted bone regeneration continuously. (3) AGM recruited bone marrow mesenchymal stem cells (BMSCs) and promote their proliferation, migration, and osteogenic differentiation. Thus, AGM developed in this study can improve osteogenesis, and provide new guidance for the development of clinical bone grafts.

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Special Issue: Application of Extracellular Matrix in Regenerative Medicine

Applied Sciences ◽

10.3390/app11073262 ◽

2021 ◽

Vol 11 (7) ◽

pp. 3262

Author(s):

Neill J. Turner

Keyword(s):

Extracellular Matrix ◽

Regenerative Medicine ◽

Wound Repair ◽

Three Dimensional ◽

Dynamic Structure ◽

Scaffold Material ◽

Special Issue ◽

Organ Regeneration ◽

Scaffold Materials ◽

The Many

The present Special Issue comprises a collection of articles addressing the many ways in which extracellular matrix (ECM), or its components parts, can be used in regenerative medicine applications. ECM is a dynamic structure, composed of a three-dimensional architecture of fibrous proteins, proteoglycans, and glycosaminoglycans, synthesized by the resident cells. Consequently, ECM can be considered as nature’s ideal biologic scaffold material. The articles in this Special Issue cover a range of topics from the use of ECM components to manufacture scaffold materials, understanding how changes in ECM composition can lead to the development of disease, and how decellularization techniques can be used to develop tissue-derived ECM scaffolds for whole organ regeneration and wound repair. This editorial briefly summarizes the most interesting aspects of these articles.

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Critical evaluation of stents in coronary angioplasty: a systematic review

BioMedical Engineering OnLine ◽

10.1186/s12938-021-00883-7 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Joseph Robert Stevens ◽

Ava Zamani ◽

James Ian Atkins Osborne ◽

Reza Zamani ◽

Mohammad Akrami

Keyword(s):

Systematic Review ◽

Success Rate ◽

Coronary Angioplasty ◽

Critical Evaluation ◽

Bare Metal Stents ◽

Coronary Stent ◽

Metal Stents ◽

Stent Design ◽

Scaffold Materials ◽

Artery Disease

Abstract Background Coronary stents are routinely placed in the treatment and prophylaxis of coronary artery disease (CAD). Current coronary stent designs are prone to developing blockages: in-stent thrombosis (IST) and in-stent re-stenosis (ISR). This is a systematic review of the design of current coronary stent models, their structural properties and their modes of application, with a focus on their associated risks of IST and ISR. The primary aim of this review is to identify the best stent design features for reducing the risk of IST and ISR. To review the three major types of stents used in clinical settings today, determining best and relevant clinical practice by exploring which types and features of offer improved patient outcomes regarding coronary angioplasty. This information can potentially be used to increase the success rate of coronary angioplasty and stent technology in the future taking into account costs and benefits. Methods Scientific databases were searched to find studies concerning stents. After the exclusion criteria were applied, 19 of the 3192 searched literature were included in this review. Studies investigating three major types of stent design were found: bare-metal stents (BMS), drug-eluting stents (DES) and bioresorbable stents (BRS). The number of participants varied between 14 and 1264. On average 77.4% were male, with a mean age of 64 years. Results From the findings of these studies, it is clear that DES are superior in reducing the risk of ISR when compared to BMS. Conflicting results do not clarify whether BRS are superior to DES at reducing IST occurrence, although studies into newer BRS technologies show reducing events of IST to 0, creating a promising future for BRS showing them to be non-inferior. Thinner stents were shown to reduce IST rates, due to better re-endothelialisation. Scaffold material has also been shown to play a role with cobalt alloy stents reducing the risk of IST. This study found that thinner stents that release drugs were better at preventing re-blockages. Some dissolvable stents might be better at stopping blood clots blocking the arteries when compared to metal stents. The method and procedure of implanting the stent during coronary angioplasty influences success rate of these stents, meaning stent design is not the only significant factor to consider. Conclusions Positive developments in coronary angioplasty could be made by designing new stents that encompass all the most desirable properties of existing stent technology. Further work is needed to investigate the benefits of BRS in reducing the risk of IST compared to DES, as well as to investigate the effects of different scaffold materials on IST and ISR outcomes.

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Characterization of Polycaprolactone Nanohydroxyapatite Composites with Tunable Degradability Suitable for Indirect Printing

Polymers ◽

10.3390/polym13020295 ◽

2021 ◽

Vol 13 (2) ◽

pp. 295

Author(s):

Stephanie E. Doyle ◽

Lauren Henry ◽

Ellen McGennisken ◽

Carmine Onofrillo ◽

Claudia Di Bella ◽

...

Keyword(s):

Molecular Weight ◽

Large Scale ◽

Three Dimensional ◽

Cell Number ◽

Compressive Modulus ◽

Degradation Rates ◽

Scaffold Materials ◽

Natural Tissue ◽

Complete Regeneration

Degradable bone implants are designed to foster the complete regeneration of natural tissue after large-scale loss trauma. Polycaprolactone (PCL) and hydroxyapatite (HA) composites are promising scaffold materials with superior mechanical and osteoinductive properties compared to the single materials. However, producing three-dimensional (3D) structures with high HA content as well as tuneable degradability remains a challenge. To address this issue and create homogeneously distributed PCL-nanoHA (nHA) scaffolds with tuneable degradation rates through both PCL molecular weight and nHA concentration, we conducted a detailed characterisation and comparison of a range of PCL-nHA composites across three molecular weight PCLs (14, 45, and 80 kDa) and with nHA content up to 30% w/w. In general, the addition of nHA results in an increase of viscosity for the PCL-nHA composites but has little effect on their compressive modulus. Importantly, we observe that the addition of nHA increases the rate of degradation compared to PCL alone. We show that the 45 and 80 kDa PCL-nHA groups can be fabricated via indirect 3D printing and have homogenously distributed nHA even after fabrication. Finally, the cytocompatibility of the composite materials is evaluated for the 45 and 80 kDa groups, with the results showing no significant change in cell number compared to the control. In conclusion, our analyses unveil several features that are crucial for processing the composite material into a tissue engineered implant.

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Engineering the Composition of Microfibers to Enhance the Remodeling of a Cell-Free Vascular Graft

Nanomaterials ◽

10.3390/nano11061613 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1613

Author(s):

Fang Huang ◽

Yu-Fang Hsieh ◽

Xuefeng Qiu ◽

Shyam Patel ◽

Song Li

Keyword(s):

Vascular Graft ◽

Animal Studies ◽

Vascular Grafts ◽

Cell Infiltration ◽

Tubular Scaffold ◽

Base Polymer ◽

A Cell ◽

Scaffold Materials ◽

Stromal Cell Derived Factor ◽

Technology Blending

The remodeling of vascular grafts is critical for blood vessel regeneration. However, most scaffold materials have limited cell infiltration. In this study, we designed and fabricated a scaffold that incorporates a fast-degrading polymer polydioxanone (PDO) into the microfibrous structure by means of electrospinning technology. Blending PDO with base polymer decreases the density of electrospun microfibers yet did not compromise the mechanical and structural properties of the scaffold, and effectively enhanced cell infiltration. We then used this technique to fabricate a tubular scaffold with heparin conjugated to the surface to suppress thrombosis, and the construct was implanted into the carotid artery as a vascular graft in animal studies. This graft significantly promoted cell infiltration, and the biochemical cues such as immobilized stromal cell-derived factor-1α further enhanced cell recruitment and the long-term patency of the grafts. This work provides an approach to optimize the microfeatures of vascular grafts, and will have broad applications in scaffold design and fabrication for regenerative engineering.

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Preparation of hydrophilic poly(l-lactide) electrospun fibrous scaffolds modified with chitosan for enhanced cell biocompatibility

Polymer ◽

10.1016/j.polymer.2012.03.039 ◽

2012 ◽

Vol 53 (11) ◽

pp. 2298-2305 ◽

Cited By ~ 72

Author(s):

Wenguo Cui ◽

Liying Cheng ◽

Haiyan Li ◽

Yue Zhou ◽

Yuguang Zhang ◽

...

Keyword(s):

Fibrous Scaffolds ◽

Cell Biocompatibility

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ELECTROSPINNING OF BIOMATERIALS AND THEIR APPLICATIONS IN TISSUE ENGINEERING

Nano LIFE ◽

10.1142/s1793984412300105 ◽

2012 ◽

Vol 02 (04) ◽

pp. 1230010 ◽

Cited By ~ 2

Author(s):

JEN-CHIEH WU ◽

H. PETER LORENZ

Keyword(s):

Tissue Engineering ◽

Electrospinning Process ◽

Polymer Fibers ◽

Nanometer Scale ◽

High Porosity ◽

Electrospinning Technique ◽

Engineering Research ◽

Fibrous Scaffolds ◽

Surface Areas ◽

Tissue Engineering Research

Electrospinning is a process for generating micrometer or nanometer scale polymer fibers with large surface areas and high porosity. For tissue engineering research, the electrospinning technique provides a quick way to fabricate fibrous scaffolds with dimensions comparable to the extracellular matrix (ECM). A variety of materials can be used in the electrospinning process, including natural biomaterials as well as synthetic polymers. The natural biomaterials have advantages such as excellent biocompatibility and biodegradability, which can be more suitable for making biomimic scaffolds. In the last two decades, there have been growing numbers of studies of biomaterial fibrous scaffolds using the electrospinning process. In this review, we will discuss biomaterials in the electrospinning process and their applications in tissue engineering.

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