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Hidalgo-Alvarez V, Dhowre HS, Kingston OA, Sheridan CM, Levis HJ. Biofabrication of Artificial Stem Cell Niches in the Anterior Ocular Segment. Bioengineering (Basel) 2021; 8:135. [PMID: 34677208 PMCID: PMC8533470 DOI: 10.3390/bioengineering8100135] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/27/2021] [Accepted: 09/27/2021] [Indexed: 11/16/2022] Open
Abstract
The anterior segment of the eye is a complex set of structures that collectively act to maintain the integrity of the globe and direct light towards the posteriorly located retina. The eye is exposed to numerous physical and environmental insults such as infection, UV radiation, physical or chemical injuries. Loss of transparency to the cornea or lens (cataract) and dysfunctional regulation of intra ocular pressure (glaucoma) are leading causes of worldwide blindness. Whilst traditional therapeutic approaches can improve vision, their effect often fails to control the multiple pathological events that lead to long-term vision loss. Regenerative medicine approaches in the eye have already had success with ocular stem cell therapy and ex vivo production of cornea and conjunctival tissue for transplant recovering patients' vision. However, advancements are required to increase the efficacy of these as well as develop other ocular cell therapies. One of the most important challenges that determines the success of regenerative approaches is the preservation of the stem cell properties during expansion culture in vitro. To achieve this, the environment must provide the physical, chemical and biological factors that ensure the maintenance of their undifferentiated state, as well as their proliferative capacity. This is likely to be accomplished by replicating the natural stem cell niche in vitro. Due to the complex nature of the cell microenvironment, the creation of such artificial niches requires the use of bioengineering techniques which can replicate the physico-chemical properties and the dynamic cell-extracellular matrix interactions that maintain the stem cell phenotype. This review discusses the progress made in the replication of stem cell niches from the anterior ocular segment by using bioengineering approaches and their therapeutic implications.
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Affiliation(s)
- Veronica Hidalgo-Alvarez
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Hala S. Dhowre
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
| | - Olivia A. Kingston
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
| | - Carl M. Sheridan
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
| | - Hannah J. Levis
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L7 8TX, UK; (H.S.D.); (O.A.K.)
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Bazgir M, Zhang W, Zhang X, Elies J, Saeinasab M, Coates P, Youseffi M, Sefat F. Degradation and Characterisation of Electrospun Polycaprolactone (PCL) and Poly(lactic-co-glycolic acid) (PLGA) Scaffolds for Vascular Tissue Engineering. MATERIALS (BASEL, SWITZERLAND) 2021; 14:4773. [PMID: 34500862 PMCID: PMC8432541 DOI: 10.3390/ma14174773] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/12/2021] [Accepted: 08/16/2021] [Indexed: 11/16/2022]
Abstract
The current study aimed to evaluate the characteristics and the effects of degradation on the structural properties of Poly(lactic-co-glycolic acid) (PLGA)- and polycaprolactone (PCL)-based nanofibrous scaffolds. Six scaffolds were prepared by electrospinning, three with PCL 15% (w/v) and three with PLGA 10% (w/v), with electrospinning processing times of 30, 60 and 90 min. Both types of scaffolds displayed more robust mechanical properties with increased spinning times. The tensile strength of both scaffolds with 90-min electrospun membranes did not show a significant difference in their strengths, as the PCL and PLGA scaffolds measured at 1.492 MPa ± 0.378 SD and 1.764 MPa ± 0.7982 SD, respectively. All membranes were shown to be hydrophobic under a wettability test. A degradation behaviour study was performed by immersing all scaffolds in phosphate-buffered saline (PBS) solution at room temperature for 12 weeks and for 4 weeks at 37 °C. The effects of degradation were monitored by taking each sample out of the PBS solution every week, and the structural changes were investigated under a scanning electron microscope (SEM). The PCL and PLGA scaffolds showed excellent fibre structure with adequate degradation, and the fibre diameter, measured over time, showed slight increase in size. Therefore, as an example of fibre water intake and progressive degradation, the scaffold's percentage weight loss increased each week, further supporting the porous membrane's degradability. The pore size and the porosity percentage of all scaffolds decreased substantially over the degradation period. The conclusion drawn from this experiment is that PCL and PLGA hold great promise for tissue engineering and regenerative medicine applications.
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Affiliation(s)
- Morteza Bazgir
- Department of Biomedical and Electronics Engineering, School of Engineering, University of Bradford, Bradford BD7 1DP, UK; (M.B.); (M.Y.)
| | - Wei Zhang
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu 610065, China;
- Advanced Polymer Materials Research Center, Sichuan University, Shishi 362700, China
| | - Ximu Zhang
- Chongqing Key Laboratory of Oral Disease and Biomedical Sciences and Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Stomatological Hospital of Chongqing Medical University, Chongqing 401174, China;
| | - Jacobo Elies
- Faculty of Life Sciences, School of Pharmacy and Medical Sciences, University of Bradford, Bradford BD7 1DP, UK;
| | - Morvarid Saeinasab
- Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad 9177948974, Iran;
| | - Phil Coates
- Interdisciplinary Research Centre in Polymer Science and Technology (Polymer IRC), University of Bradford, Bradford BD7 1DP, UK;
| | - Mansour Youseffi
- Department of Biomedical and Electronics Engineering, School of Engineering, University of Bradford, Bradford BD7 1DP, UK; (M.B.); (M.Y.)
| | - Farshid Sefat
- Department of Biomedical and Electronics Engineering, School of Engineering, University of Bradford, Bradford BD7 1DP, UK; (M.B.); (M.Y.)
- Interdisciplinary Research Centre in Polymer Science and Technology (Polymer IRC), University of Bradford, Bradford BD7 1DP, UK;
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Abdul-Al M, Kyeremeh GK, Saeinasab M, Heidari Keshel S, Sefat F. Stem Cell Niche Microenvironment: Review. Bioengineering (Basel) 2021; 8:bioengineering8080108. [PMID: 34436111 PMCID: PMC8389324 DOI: 10.3390/bioengineering8080108] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 12/13/2022] Open
Abstract
The cornea comprises a pool of self-regenerating epithelial cells that are crucial to preserving clarity and visibility. Limbal epithelial stem cells (LESCs), which live in a specialized stem cell niche (SCN), are crucial for the survival of the human corneal epithelium. They live at the bottom of the limbal crypts, in a physically enclosed microenvironment with a number of neighboring niche cells. Scientists also simplified features of these diverse microenvironments for more analysis in situ by designing and recreating features of different SCNs. Recent methods for regenerating the corneal epithelium after serious trauma, including burns and allergic assaults, focus mainly on regenerating the LESCs. Mesenchymal stem cells, which can transform into self-renewing and skeletal tissues, hold immense interest for tissue engineering and innovative medicinal exploration. This review summarizes all types of LESCs, identity and location of the human epithelial stem cells (HESCs), reconstruction of LSCN and artificial stem cells for self-renewal.
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Affiliation(s)
- Mohamed Abdul-Al
- Department of Biomedical and Electronics Engineering, School of Engineering, University of Bradford, Bradford BD71DP, UK; (M.A.-A.); (G.K.K.)
| | - George Kumi Kyeremeh
- Department of Biomedical and Electronics Engineering, School of Engineering, University of Bradford, Bradford BD71DP, UK; (M.A.-A.); (G.K.K.)
| | - Morvarid Saeinasab
- Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad 91779 48974, Iran;
| | - Saeed Heidari Keshel
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran 19839 69411, Iran;
| | - Farshid Sefat
- Department of Biomedical and Electronics Engineering, School of Engineering, University of Bradford, Bradford BD71DP, UK; (M.A.-A.); (G.K.K.)
- Interdisciplinary Research Centre in Polymer Science & Technology (Polymer IRC), University of Bradford, Bradford BD71DP, UK
- Correspondence:
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Bioactive and Topographically-Modified Electrospun Membranes for the Creation of New Bone Regeneration Models. Processes (Basel) 2020. [DOI: 10.3390/pr8111341] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Bone injuries that arise from trauma, cancer treatment, or infection are a major and growing global challenge. An increasingly ageing population plays a key role in this, since a growing number of fractures are due to diseases such as osteoporosis, which place a burden on healthcare systems. Current reparative strategies do not sufficiently consider cell-substrate interactions that are found in healthy tissues; therefore, the need for more complex models is clear. The creation of in vitro defined 3D microenvironments is an emerging topographically-orientated approach that provides opportunities to apply knowledge of cell migration and differentiation mechanisms to the creation of new cell substrates. Moreover, introducing biofunctional agents within in vitro models for bone regeneration has allowed, to a certain degree, the control of cell fate towards osteogenic pathways. In this research, we applied three methods for functionalizing spatially-confined electrospun artificial microenvironments that presented relevant components of the native bone stem cell niche. The biological and osteogenic behaviors of mesenchymal stromal cells (MSCs) were investigated on electrospun micro-fabricated scaffolds functionalized with extracellular matrix (ECM) proteins (collagen I), glycosaminoglycans (heparin), and ceramic-based materials (bioglass). Collagen, heparin, and bioglass (BG) were successfully included in the models without modifying the fibrous structures offered by the polycaprolactone (PCL) scaffolds. Mesenchymal stromal cells (MSCs) were successfully seeded in all the biofunctional scaffolds and they showed an increase in alkaline phosphatase production when exposed to PCL/BG composites. This research demonstrates the feasibility of manufacturing smart and hierarchical artificial microenvironments for studying stem cell behavior and ultimately the potential of incorporating these artificial microenvironments into multifunctional membranes for bone tissue regeneration
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Mahdavi SS, Abdekhodaie MJ, Mashayekhan S, Baradaran-Rafii A, Djalilian AR. Bioengineering Approaches for Corneal Regenerative Medicine. Tissue Eng Regen Med 2020; 17:567-593. [PMID: 32696417 PMCID: PMC7373337 DOI: 10.1007/s13770-020-00262-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Since the cornea is responsible for transmitting and focusing light into the eye, injury or pathology affecting any layer of the cornea can cause a detrimental effect on visual acuity. Aging is also a reason for corneal degeneration. Depending on the level of the injury, conservative therapies and donor tissue transplantation are the most common treatments for corneal diseases. Not only is there a lack of donor tissue and risk of infection/rejection, but the inherent ability of corneal cells and layers to regenerate has led to research in regenerative approaches and treatments. METHODS In this review, we first discussed the anatomy of the cornea and the required properties for reconstructing layers of the cornea. Regenerative approaches are divided into two main categories; using direct cell/growth factor delivery or using scaffold-based cell delivery. It is expected delivered cells migrate and integrate into the host tissue and restore its structure and function to restore vision. Growth factor delivery also has shown promising results for corneal surface regeneration. Scaffold-based approaches are categorized based on the type of scaffold, since it has a significant impact on the efficiency of regeneration, into the hydrogel and non-hydrogel based scaffolds. Various types of cells, biomaterials, and techniques are well covered. RESULTS The most important characteristics to be considered for biomaterials in corneal regeneration are suitable mechanical properties, biocompatibility, biodegradability, and transparency. Moreover, a curved shape structure and spatial arrangement of the fibrils have been shown to mimic the corneal extracellular matrix for cells and enhance cell differentiation. CONCLUSION Tissue engineering and regenerative medicine approaches showed to have promising outcomes for corneal regeneration. However, besides proper mechanical and optical properties, other factors such as appropriate sterilization method, storage, shelf life and etc. should be taken into account in order to develop an engineered cornea for clinical trials.
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Affiliation(s)
- S Sharareh Mahdavi
- Department of Chemical and Petroleum Engineering, Sharif University of Technology, 1393 Azadi Ave., Tehran, 11365-11155, Iran
| | - Mohammad J Abdekhodaie
- Department of Chemical and Petroleum Engineering, Sharif University of Technology, 1393 Azadi Ave., Tehran, 11365-11155, Iran.
| | - Shohreh Mashayekhan
- Department of Chemical and Petroleum Engineering, Sharif University of Technology, 1393 Azadi Ave., Tehran, 11365-11155, Iran
| | - Alireza Baradaran-Rafii
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, SBUMS, Arabi Ave, Daneshjoo Blvd, Velenjak, Tehran, 19839-63113, Iran
| | - Ali R Djalilian
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1200 W Harrison St, Chicago, IL, 60607, USA
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Mobaraki M, Abbasi R, Omidian Vandchali S, Ghaffari M, Moztarzadeh F, Mozafari M. Corneal Repair and Regeneration: Current Concepts and Future Directions. Front Bioeng Biotechnol 2019; 7:135. [PMID: 31245365 PMCID: PMC6579817 DOI: 10.3389/fbioe.2019.00135] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 05/20/2019] [Indexed: 12/13/2022] Open
Abstract
The cornea is a unique tissue and the most powerful focusing element of the eye, known as a window to the eye. Infectious or non-infectious diseases might cause severe visual impairments that need medical intervention to restore patients' vision. The most prominent characteristics of the cornea are its mechanical strength and transparency, which are indeed the most important criteria considerations when reconstructing the injured cornea. Corneal strength comes from about 200 collagen lamellae which criss-cross the cornea in different directions and comprise nearly 90% of the thickness of the cornea. Regarding corneal transparency, the specific characteristics of the cornea include its immune and angiogenic privilege besides its limbus zone. On the other hand, angiogenic privilege involves several active cascades in which anti-angiogenic factors are produced to compensate for the enhanced production of proangiogenic factors after wound healing. Limbus of the cornea forms a border between the corneal and conjunctival epithelium, and its limbal stem cells (LSCs) are essential in maintenance and repair of the adult cornea through its support of corneal epithelial tissue repair and regeneration. As a result, the main factors which threaten the corneal clarity are inflammatory reactions, neovascularization, and limbal deficiency. In fact, the influx of inflammatory cells causes scar formation and destruction of the limbus zone. Current studies about wound healing treatment focus on corneal characteristics such as the immune response, angiogenesis, and cell signaling. In this review, studied topics related to wound healing and new approaches in cornea regeneration, which are mostly related to the criteria mentioned above, will be discussed.
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Affiliation(s)
- Mohammadmahdi Mobaraki
- Biomaterials Group, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Reza Abbasi
- Biomaterials Group, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Sajjad Omidian Vandchali
- Biomaterials Group, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Maryam Ghaffari
- Biomaterials Group, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Fathollah Moztarzadeh
- Biomaterials Group, Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Masoud Mozafari
- Department of Tissue Engineering and Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
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Aligned electrospun cellulose scaffolds coated with rhBMP-2 for both in vitro and in vivo bone tissue engineering. Carbohydr Polym 2019; 213:27-38. [DOI: 10.1016/j.carbpol.2019.02.038] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 02/12/2019] [Accepted: 02/12/2019] [Indexed: 12/13/2022]
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8
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Asencio IO, Mittar S, Sherborne C, Raza A, Claeyssens F, MacNeil S. A methodology for the production of microfabricated electrospun membranes for the creation of new skin regeneration models. J Tissue Eng 2018; 9:2041731418799851. [PMID: 30263105 PMCID: PMC6153546 DOI: 10.1177/2041731418799851] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/16/2018] [Indexed: 12/22/2022] Open
Abstract
The continual renewal of the epidermis is thought to be related to the presence of populations of epidermal stem cells residing in physically protected microenvironments (rete ridges) directly influenced by the presence of mesenchymal fibroblasts. Current skin in vitro models do acknowledge the influence of stromal fibroblasts in skin reorganisation but the study of the effect of the rete ridge-microenvironment on epidermal renewal still remains a rich topic for exploration. We suggest there is a need for the development of new in vitro models in which to study epithelial stem cell behaviour prior to translating these models into the design of new cell-free biomaterial devices for skin reconstruction. In this study, we aimed to develop new prototype epidermal-like layers containing pseudo-rete ridge structures for studying the effect of topographical cues on epithelial cell behaviour. The models were designed using a range of three-dimensional electrospun microfabricated scaffolds. This was achieved via the utilisation of polyethylene glycol diacrylate to produce a reusable template over which poly(3-hydrroxybutyrate-co-3-hydroxyvalerate) was electrospun. Initial investigations studied the behaviour of keratinocytes cultured on models using plain scaffolds (without the presence of intricate topography) versus keratinocytes cultured on scaffolds containing microfeatures.
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Affiliation(s)
- Ilida Ortega Asencio
- Bioengineering and Health Technologies
Group, The School of Clinical Dentistry, The University of Sheffield, Sheffield,
UK
| | - Shweta Mittar
- Biomaterials and Tissue Engineering
Group, Department of Materials Science and Engineering, Kroto Research Institute,
The University of Sheffield, Sheffield, UK
| | - Colin Sherborne
- Biomaterials and Tissue Engineering
Group, Department of Materials Science and Engineering, Kroto Research Institute,
The University of Sheffield, Sheffield, UK
| | - Ahtasham Raza
- Biomaterials and Tissue Engineering
Group, Department of Materials Science and Engineering, Kroto Research Institute,
The University of Sheffield, Sheffield, UK
| | - Frederik Claeyssens
- Biomaterials and Tissue Engineering
Group, Department of Materials Science and Engineering, Kroto Research Institute,
The University of Sheffield, Sheffield, UK
| | - Sheila MacNeil
- Biomaterials and Tissue Engineering
Group, Department of Materials Science and Engineering, Kroto Research Institute,
The University of Sheffield, Sheffield, UK
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Gentile P, McColgan-Bannon K, Gianone NC, Sefat F, Dalgarno K, Ferreira AM. Biosynthetic PCL-graft-Collagen Bulk Material for Tissue Engineering Applications. MATERIALS (BASEL, SWITZERLAND) 2017; 10:E693. [PMID: 28773053 PMCID: PMC5551736 DOI: 10.3390/ma10070693] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 05/17/2017] [Accepted: 06/19/2017] [Indexed: 12/12/2022]
Abstract
Biosynthetic materials have emerged as one of the most exciting and productive fields in polymer chemistry due to their widespread adoption and potential applications in tissue engineering (TE) research. In this work, we report the synthesis of a poly(ε-caprolactone)-graft-collagen (PCL-g-Coll) copolymer. We combine its good mechanical and biodegradable PCL properties with the great biological properties of type I collagen as a functional material for TE. PCL, previously dissolved in dimethylformamide/dichloromethane mixture, and reacted with collagen using carbodiimide coupling chemistry. The synthesised material was characterised physically, chemically and biologically, using pure PCL and PCL/Coll blend samples as control. Infrared spectroscopy evidenced the presence of amide I and II peaks for the conjugated material. Similarly, XPS evidenced the presence of C-N and N-C=O bonds (8.96 ± 2.02% and 8.52 ± 0.63%; respectively) for PCL-g-Coll. Static contact angles showed a slight decrease in the conjugated sample. However, good biocompatibility and metabolic activity was obtained on PCL-g-Coll films compared to PCL and blend controls. After 3 days of culture, fibroblasts exhibited a spindle-like morphology, spreading homogeneously along the PCL-g-Coll film surface. We have engineered a functional biosynthetic polymer that can be processed by electrospinning.
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Affiliation(s)
- Piergiorgio Gentile
- School of Mechanical and Systems Engineering, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK.
| | - Kegan McColgan-Bannon
- School of Mechanical and Systems Engineering, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK.
| | - Nicolò Ceretto Gianone
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, 10129 Turin, Italy.
| | - Farshid Sefat
- Department of Medical Engineering, School of Engineering, University of Bradford, Bradford BD7 1DP, UK.
| | - Kenneth Dalgarno
- School of Mechanical and Systems Engineering, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK.
| | - Ana Marina Ferreira
- School of Mechanical and Systems Engineering, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK.
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Krishna L, Dhamodaran K, Jayadev C, Chatterjee K, Shetty R, Khora SS, Das D. Nanostructured scaffold as a determinant of stem cell fate. Stem Cell Res Ther 2016; 7:188. [PMID: 28038681 PMCID: PMC5203716 DOI: 10.1186/s13287-016-0440-y] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The functionality of stem cells is tightly regulated by cues from the niche, comprising both intrinsic and extrinsic cell signals. Besides chemical and growth factors, biophysical signals are important components of extrinsic signals that dictate the stem cell properties. The materials used in the fabrication of scaffolds provide the chemical cues whereas the shape of the scaffolds provides the biophysical cues. The effect of the chemical composition of the scaffolds on stem cell fate is well researched. Biophysical signals such as nanotopography, mechanical forces, stiffness of the matrix, and roughness of the biomaterial influence the fate of stem cells. However, not much is known about their role in signaling crosstalk, stem cell maintenance, and directed differentiation. Among the various techniques for scaffold design, nanotechnology has special significance. The role of nanoscale topography in scaffold design for the regulation of stem cell behavior has gained importance in regenerative medicine. Nanotechnology allows manipulation of highly advanced surfaces/scaffolds for optimal regulation of cellular behavior. Techniques such as electrospinning, soft lithography, microfluidics, carbon nanotubes, and nanostructured hydrogel are described in this review, along with their potential usage in regenerative medicine. We have also provided a brief insight into the potential signaling crosstalk that is triggered by nanomaterials that dictate a specific outcome of stem cells. This concise review compiles recent developments in nanoscale architecture and its importance in directing stem cell differentiation for prospective therapeutic applications.
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Affiliation(s)
- Lekshmi Krishna
- Stem Cell Research Lab, GROW Lab, Narayana Nethralaya Foundation, Bangalore, Karnataka, India.,School of Bioscience and Technology, VIT University, Vellore, Tamil Nadu, India
| | - Kamesh Dhamodaran
- Stem Cell Research Lab, GROW Lab, Narayana Nethralaya Foundation, Bangalore, Karnataka, India.,School of Bioscience and Technology, VIT University, Vellore, Tamil Nadu, India
| | - Chaitra Jayadev
- Vitreoretina Services, Narayana Nethralaya Eye Hospital, Bangalore, Karnataka, India
| | - Kaushik Chatterjee
- Department of Materials Engineering, Indian Institute of Science, Bangalore, Karnataka, India
| | - Rohit Shetty
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bangalore, Karnataka, India
| | - S S Khora
- School of Bioscience and Technology, VIT University, Vellore, Tamil Nadu, India
| | - Debashish Das
- Stem Cell Research Lab, GROW Lab, Narayana Nethralaya Foundation, Bangalore, Karnataka, India.
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11
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Kong B, Mi S. Electrospun Scaffolds for Corneal Tissue Engineering: A Review. MATERIALS 2016; 9:ma9080614. [PMID: 28773745 PMCID: PMC5509008 DOI: 10.3390/ma9080614] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 06/30/2016] [Accepted: 07/04/2016] [Indexed: 01/30/2023]
Abstract
Corneal diseases constitute the second leading cause of vision loss and affect more than 10 million people globally. As there is a severe shortage of fresh donated corneas and an unknown risk of immune rejection with traditional heterografts, it is very important and urgent to construct a corneal equivalent to replace pathologic corneal tissue. Corneal tissue engineering has emerged as a practical strategy to develop corneal tissue substitutes, and the design of a scaffold with mechanical properties and transparency similar to that of natural cornea is paramount for the regeneration of corneal tissues. Nanofibrous scaffolds produced by electrospinning have high surface area-to-volume ratios and porosity that simulate the structure of protein fibers in native extra cellular matrix (ECM). The versatilities of electrospinning of polymer components, fiber structures, and functionalization have made the fabrication of nanofibrous scaffolds with suitable mechanical strength, transparency and biological properties for corneal tissue engineering feasible. In this paper, we review the recent developments of electrospun scaffolds for engineering corneal tissues, mainly including electrospun materials (single and blended polymers), fiber structures (isotropic or anisotropic), functionalization (improved mechanical properties and transparency), applications (corneal cell survival, maintenance of phenotype and formation of corneal tissue) and future development perspectives.
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Affiliation(s)
- Bin Kong
- Biomanufacturing Engineering Laboratory, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
- Macromolecular Platforms for Translational Medicine and Bio-Manufacturing Laboratory, Tsinghua-Berkeley Shenzhen Insititute, Shenzhen 518055, China.
| | - Shengli Mi
- Biomanufacturing Engineering Laboratory, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
- Open FIESTA Center, Tsinghua University, Shenzhen 518055, China.
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12
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Valente TAM, Silva DM, Gomes PS, Fernandes MH, Santos JD, Sencadas V. Effect of Sterilization Methods on Electrospun Poly(lactic acid) (PLA) Fiber Alignment for Biomedical Applications. ACS APPLIED MATERIALS & INTERFACES 2016; 8:3241-3249. [PMID: 26756809 DOI: 10.1021/acsami.5b10869] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Medically approved sterility methods should be a major concern when developing a polymeric scaffold, mainly when commercialization is envisaged. In the present work, poly(lactic acid) (PLA) fiber membranes were processed by electrospinning with random and aligned fiber alignment and sterilized under UV, ethylene oxide (EO), and γ-radiation, the most common ones for clinical applications. It was observed that UV light and γ-radiation do not influence fiber morphology or alignment, while electrospun samples treated with EO lead to fiber orientation loss and morphology changing from cylindrical fibers to ribbon-like structures, accompanied to an increase of polymer crystallinity up to 28%. UV light and γ-radiation sterilization methods showed to be less harmful to polymer morphology, without significant changes in polymer thermal and mechanical properties, but a slight increase of polymer wettability was detected, especially for the samples treated with UV radiation. In vitro results indicate that both UV and γ-radiation treatments of PLA membranes allow the adhesion and proliferation of MG 63 osteoblastic cells in a close interaction with the fiber meshes and with a growth pattern highly sensitive to the underlying random or aligned fiber orientation. These results are suggestive of the potential of both γ-radiation sterilized PLA membranes for clinical applications in regenerative medicine, especially those where customized membrane morphology and fiber alignment is an important issue.
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Affiliation(s)
- T A M Valente
- Departamento de Engenharia Metalúrgica e Materiais, Faculdade de Engenharia, Universidade do Porto , Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - D M Silva
- Biosckin, Molecular, and Cell Therapies, SA. Parque Tecnológico da Maia-Tecmaia , Rua Eng.° Frederico Ulrich, 2650, 4470-605 Maia, Portugal
| | - P S Gomes
- Faculdade de Medicina Dentária, Universidade do Porto , Rua Dr. Manuel Pereira da Silva, 4200-393 Porto, Portugal
| | - M H Fernandes
- Faculdade de Medicina Dentária, Universidade do Porto , Rua Dr. Manuel Pereira da Silva, 4200-393 Porto, Portugal
| | - J D Santos
- Departamento de Engenharia Metalúrgica e Materiais, Faculdade de Engenharia, Universidade do Porto , Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
- CEMUC, Departamento de Engenharia Metalúrgica e Materiais, Faculdade de Engenharia, Universidade do Porto , Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
| | - V Sencadas
- School of Mechanical, Materials, and Mechatronics Engineering, University of Wollongong , Wollongong, NSW 2522, Australia
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Abstract
This work reports first steps towards the development of artificial neural stem cell microenvironments for the control and assessment of neural stem cell behaviour. Stem cells have been shown to be found in specific, supportive microenvironments (niches) and are believed to play an important role in tissue regeneration mechanisms. These environments are intricate spaces with chemical and biological features. Here we present work towards the development of physically defined microdevices in which neural and neural stem cells can be studied in 3-dimensions. We have approached this challenge by creating bespoke, microstructured polymer environments using both 2-photon polymerisation and soft lithography techniques. Specifically, we have designed and fabricated biodegradable microwell-shaped devices using an in house synthetized polymer (4-arm photocurable poly-lactid acid) on a bespoke 2-photon polymerisation (2PP) set-up. We have studied swelling and degradation of the constructs as well as biocompatibility. Moreover, we have explored the potential of these constructs as artificial neural cell substrates by culturing NG108-15 cells (mouse neuroblastoma; rat glioma hybrid) and human neural progenitor cells on the microstructures. Finally, we have studied the effects of our artificial microenvironments upon neurite length and cell density.
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