Commercializing Electrospun Scaffolds for Pluripotent Stem Cell

Electrospinning 2017; 1:62–72

Research Article

Nima Khadem Mohtaram, Vahid Karamzadeh, Yousef Shafieyan, and Stephanie M. Willerth* Commercializing Electrospun Scaffolds for Pluripotent Stem Cell-based Tissue Engineering Applications https://doi.org/10.1515/esp-2017-0003 Received May 08, 2017; accepted July 05, 2017 1 Pluripotent Stem Cells and their

Abstract: Tissue engineering, the process of combining Promise for Tissue Engineering bioactive scaffolds often with cells to produce replace- Applications ments for damaged organs, represents an enormous market opportunity. This review critically evaluates the com- Scientists had long hypothesized about the existence of mercialization potential of electrospun scaffolds for ap- stem cells in the body before confirming their existence plications in stem cell biology, including tissue engineer- experimentally [1]. These stem cells possess two distinct ing. First, it provides an overview of pluripotent stem cells properties that distinguish them from other types of cells (PSCs) and their defining properties, pluripotency and the present in an organism [2]. The first property of a stem cell ability to self-renew. These cells serve as an important tool is the ability to become or differentiate into multiple types for engineering tissues, including for clinical applications. of cells. Their second property is the ability to self-renew, Next, we review the technique of electrospinning and its meaning that they can produce more stem cells. Both prop- promise for fabricating cell culture substrates and scaf- erties make stem cells a valuable tool for engineering tis- folds for directing tissue formation from stem cells and sues. The process of tissue engineering combines cells, compare these scaffolds to existing technologies, such as biochemical cues, and biomaterial scaffolds as a way of hydrogels. We address the associated market for electro- producing substitutes for diseased or damaged tissues and spun scaffolds for PSCs and its potential for growth along it represents a lucrative market valued in the billions of with highlighting the importance of 3D cell culture sub- dollars that is growing rapidly [3]. In terms of the history strates for PSCs by analyzing the net capital invested in of how stem cells were discovered, the Canadian duo of Dr. this market and the associated growth rate. This review Ernest Till and Dr. James McCulloch first identified mes- finishes by detailing the current state of commercializing enchymal stem cells in the 1960s [4–6]. However, these electrospun scaffolds along with pathways for translating cells were limited in terms of the types of mature cells that these scaffolds from research laboratories into success- they could become as they were derived from a specific tis- ful start-up companies and the associated challenges with sue. Thus, scientists aimed to find a more versatile type of this process. stem cell. One of the most desirable properties a stem cell can Keywords: Pluripotent stem cells, Electrospinning, possess is pluripotency, meaning that these cells can pro- Nanofibers, Microfibers, Commercialization, Tissue en- duce any cell type found in the organism from which they gineering were derived. Pluripotent stem cell lines are considered to be undifferentiated, reflecting this property, and these cells differentiate into mature phenotypes. The isolation *Corresponding Author: Stephanie M. Willerth: Department and culture of pluripotent stem cells (PSCs) occurred much of Mechanical Engineering, University of Victoria, Victoria, BC, later than the initial discovery of stem cells with these cells Canada; Division of Medical Sciences, University of Victoria, Vic- being isolated from mouse embryos in 1981 [7]. These PSCs toria, BC, Canada; Centre for Biomedical Research, Victoria, BC, Canada; International Collaboration On Repair Discoveries, Vancou- were termed embryonic stem cells (ESCs), reflecting the ver, BC, Canada; Department of Biochemistry, University of British Columbia, Vancouver, BC, Canada; Email: [email protected]; Tel.: 250-721-7303; Fax: 250-721-6051 Nima Khadem Mohtaram, Yousef Shafieyan: CellFace Ltd, Vahid Karamzadeh: Department of Mechanical Engineering, Con- Toronto, ON, Canada cordia University, Montreal, QC, Canada

Open Access. © 2017 N. K. Mohtaram et al., published by De Gruyter Open. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License Commercializing Electrospun Scaffolds for Tissue Engineering Applications Ë 63 fact that they were derived from the embryo, which is an the first clinical trial evaluating human iPSC-derived reti- early stage of development that mammals go through in nal pigment epithelial cells is underway [19]. More on the the process of becoming a mature organism. Deriving such translation of PSC-derived therapies for clinical applica- pluripotent stem cells from human embryos was challeng- tions can be found in a recent review from Nature Reviews ing – both in terms of finding sufficient donor embryos and Molecular Cell Biology [20]. successfully completing the isolation process. Thus, it was While their pluripotency and their ability to self-renew not until 1998 that human ESC lines were derived in the serve as attractive properties for applications in tissue en- Thomson lab at the University of Wisconsin-Madison [8]. gineering, pluripotent stem cell lines, including ESCs and The generation of human ESCs lines then made it possible iPSCs, possess several limitations. One major concern is to engineer any type of tissue from these pluripotent cell that their ability to replicate indefinitely can lead to tu- lines. mour formation both in in vitro and in vivo settings. Thus, Significant advances were then made in understand- it is important to ensure that a chosen tissue engineering ing how to derive mature functional cells from human strategy promotes sufficient and mature differentiation of ESCs, such cardiac tissue, bone, pancreas, and nervous PSCs and avoids the presence of undifferentiated cells in tissue. These advances have resulted in two ESC-derived the construct that is to be implanted, such as in the cell products being evaluated in clinical trials. The first prod- therapies currently being evaluated in clinical trials. Un- uct, oligodendrocyte progenitor cells derived from human differentiated ESCs can be depleted using selection tech- ESCs, are being evaluated by Asterias Therapeutics (for- niques like flow cytometry or antibiotic-mediated death in merly Geron Corporation) in Phase I clinical trial for treat- combination with genetically altered cell lines [21]. A pair ing spinal cord injury [9]. Another clinical trial has exam- of studies has indicated that iPSC lines can be selected ined the ability of human ESC-derived retinal pigmented that possess a reduced risk of tumour formation [22, 23]. epithelium to promote recovery in patients suffering from As these cells can be maintained indefinitely in culture, macular degeneration, which demonstrated promising re- confirming their genomic integrity with routine karyotyp- sults [10, 11]. Many neurological diseases and disorders ing will ensure that no harmful mutations have occurred in lack true cures, making them attractive targets for cell ther- their DNA. Another approach to generating safe iPSC lines apies. In terms of pre-clinical work, it is anticipated that a uses non-integrating microRNA technology developed by Phase I clinical trial will be launched to evaluate the abil- the Nagy lab at the University of Toronto, as the transient ity of human ESC-derived dopaminergic neurons to treat expression of the pluripotency genes results in cell lines Parkinson’s Disease in the near future [12]. Other promis- without the risk of tumor formation [24]. Overall, PSCs rep- ing targets for ESC-derived therapies include treating dia- resent a powerful tool for engineering tissues, which will betes and heart disease [13, 14]. be explained in the next section. However, several issues remain with the use of hESCs. The number of cell lines derived was limited under the Bush administration as the United States restricted fund- 2 Current Status of PSCs for Tissue ing for stem cell research. As a result, researchers began to investigate alternative ways of generating PSCs. In 2006, Engineering Applications Takahashi and Yamanaka made a breakthrough discovery when they determined that four transcription factors, pro- Early work from the Langer lab explored how combina- teins which regulate the properties of cells, could be used tions of polymer scaffolds and growth factors could be to directly reprogram mouse fibroblasts back into a state of used to engineer different types of tissue from human pluripotency [15]. They named the resulting cells induced ESCs [25]. Since then, numerous studies have explored pluripotent stem cells (iPSCs). This breakthrough was fol- how to engineer functional tissues from PSCs as these cells lowed by the generation of human iPSC lines from fibrob- can become any type of tissue found in the body. The ma- lasts [16, 17]. These cells generated excitement for several jor challenge is determining the necessary set of physical reasons. First, they now enabled the generation of pluripo- and chemical cues necessary to guide these cells to form tent stem cells from specific patients, reducing the poten- functional tissues [26]. Scientists often look to the chemi- tial for immune rejection if the cells were used therapeuti- cal cues and physical structures present during tissue for- cally. It was also now possible to generate iPSC lines from mation during the process of development as a starting patients suffering from diseases, allowing the investiga- point for designing proper scaffolding for directing the dif- tion into disease mechanisms and the ability to use these ferentiation of PSCs [27]. lines for applications in drug screening [18]. In Japan, 64 Ë N. K. Mohtaram et al.

In terms of tissue engineering, the most commonly types of topography. Chemical cues can be incorporated used scaffolds are hydrogels fabricated from biomateri- into the polymer solution to enable the resulting fibers als that are used to culture, expand, and differentiate to present bioactive factors in a controlled fashion [54– PSCs [28–31]. Hydrogels consist of cross-linked polymer 56]. Two variants of the electrospinning process exist – networks that contain high water content. These hydrogels solution and melt. In solution electrospinning, the poly- can be generated from both natural and synthetic polymer is dissolved in a liquid solvent [32] with other com- mers as their properties are selected to provide a support- ponents being mixed into polymer solution to further add ive environment for controlling PSC behavior. While hy- bio-functionalities, including small molecules and macro- drogels are the most commonly used scaffolds for engi- molecules, such as proteins [34, 48, 55, 57–64]. By con- neering tissues from PSCs, electrospinning has become an trast, melt electrospinning generates a liquid polymer by increasingly popular alternative fabrication technique for heating the material until it liquifies [53]. Both electrospin- generating such scaffolds. ning techniques have been successfully applied to the field of tissue engineering as way to produce a variety of tissue types [65–68]. 3 Fabrication of Fibrous Scaffolds using Solution and Melt 4 Tissue Engineering Applications Electrospinning of Fiber-Based Scaffolds Electrospinning has been used for diverse tissue engi- Solution electrospinning can produce engineered neering applications in research laboratories [32–45]. The nanofiber scaffolds with multiple functionalities, includ- technique spins highly charged polymer solutions into ing the controlled release of morphogens and the pre- nanofibers or microfibers. In addition to the voltage field sentation of novel topographical cues. These nanofiber used to charge the polymer, other parameters play a key scaffolds have been combined with PSCs to engineer a role in this process, including collection distance between variety of tissues, including neural, cardiac, and carti- the extruded polymer and the collector, the method of lage. The Willerth lab has done extensive work designing fiber collection, needle size used for extrusion and some and fabricating such multifunctional scaffolds for promot- other material-related parameters like molecular weight, ing the neuronal differentiation of PSCs [47, 59, 69, 70]. solution concentration, viscosity and the type of solvent For instance, Mohtaram et al. showed that encapsulation used to dissolve polymer or the melting point of the poly- of retinoic acid inside engineered nanofibers with differ- mer [46–50]. A wide variety of polymers have been electro- ent topographies enhanced the neuronal differentiation spun into scaffolds, including both natural and synthetic of mouse iPSCs while guiding the outgrowth of neurites materials [51]. In terms of synthetic materials, poly (lactic- from these cells along the scaffold topography [55]. In co-glycolic acid) (PLGA) and poly (caprolactone) are pop- terms of differentiating human iPSCs into neural tissue, ular choices for electrospinning. Natural biomaterials, in- aligned nanofiber scaffolds were encapsulated with the cluding proteins like collagen, fibrin and ceramics, have protein glial derived neurotrophic factor (GDNF), which also been electrospun. However, not all types of polymers was remained bioactive as it promoted the differentiation can be electrospun as their intrinsic material properties of human iPSCs into neurons [48]. These scaffolds can dictate if and how the resulting fibers will form during the repair damaged cardiac tissue as reviewed recently [71]. fabrication process. The electrospinning process can also Such electrospun nanofiber scaffolds can direct pluripo- alter the bioactivity of natural proteins, which is an impor- tent stem cells to form functional cardiac tissue as shown tant consideration when using electrospinning to fabricate in a 2016 study [72]. Nanofiber scaffolds have also been scaffolds for PSC cultures. designed that promote the differentiation of PSCs into os- Electrospinning provides a unique opportunity to fab- teogenic lineages as a way to engineer bone tissue [73, 74]. ricate complex scaffolds that present the necessary chemi- Finally, nanofiber scaffolds generated using solution elec- cal and physical cues for promoting differentiation of both trospinning can also direct PSCs to form chondrocytes, ESCs and iPSCs [40, 44, 52, 53]. However, ensuring proper enabling the generation of cartilage [75]. simultaneous presentation of chemical and physical cues Other groups have used engineered nanofibers for using electrospinning can be challenging. The collection other applications in directing PSC behavior as detailed by method for these fibers can be altered to produce different Higuchi et al. who performed an in depth review on the Commercializing Electrospun Scaffolds for Tissue Engineering Applications Ë 65 use of electropsun materials for culturing and differenti- et al. used melt electrospun scaffolds with novel topogra- ating PSCs [76]. Besides directing stem cell differentiation, phy to direct neurite extension from differentiated neurons electrospun scaffolds can be used as a tool for expanding derived from human iPSCs [69]. These scaffolds relied on pluripotent stem cells. In particular, defined electrospun physical cues (in this case, fiber orientation) to differen- scaffolds can serve as alternative to animal derived matri- tiate PSCs. Although melt electrospinning avoids the two ces, like Matrigel, which is often used to coat 2D substrates most common issues associated with solution electrospin- for expanding undifferentiated PSCs. 3D hydrogels have ning, which are the use of toxic solvents and the lack of also been evaluated as a tool for PSC expansion as recently reproducibility, there are still challenges to be addressed. reviewed [77, 78]. One study determined that aligned and Examples include finding suitable polymers that can be random PCL, PLGA, and poly (L-lactic acid) (PLLA) elec- melted, how to incorporate bioactive molecules and drugs, trospun substrates supported the culture and expansion how to electrospin natural biomaterials, and being able to of human ESCs [79]. Recent work published in Acta Bio- generate fibers on the nanoscale. materialia showed that electrospun polystyrene scaffolds Overall, both solution and melt electrospun scaffolds could be used to culture undifferentiated hiPSCs under have shown great promise in the field of stem cell-based xeno-free conditions, providing an attractive alternative to tissue engineering. Such scaffolds can be produced in a Matrigel [80]. A recent Biomaterials papers demonstrated highly scalable manner and have utility for applications how solution electrospinning can generate fibrous scaf- in PSC culture and differentiation into functional tissue. folds that mimic the extracellular matrix, enabling the ex- Such engineered products are in high demand as more re- pansion of human PSCs [81]. Such substrates address one search funding is being invested in the field of stem cell of the major challenges in stem cell biology: producing based tissue engineering. The next section addresses the sufficient quantities of cells for therapeutic applications. market associated with such products and discusses the Although solution electrospinning remains an excellent current state of the field and its future directions. technique for fabricating 2D and 3D substrates for expanding and differentiating PSCs, many challenges exist with this technique. These challenges include the use of organic 5 3D Substrates for PSC Culture toxic solvents, which can have negative effects on cell behavior, and the difficulties of controlling the architecture As mentioned earlier, PSCs can differentiate into any cell of the electrospun scaffolds. Another issue is ensuring that type found in human body. However, the differentiation the mechanical properties of these scaffolds are consistent process requires several complicated factors and specific as they can vary during fabrication. These issues serve as environments or niches [92, 97–101]. These niches present the main obstacles to commercializing these technologies. biochemical, physical and mechanical signals to PSCs, Melt electrospinning provides an attractive alterna- which influence differentiation. Most current in vitro mod- tive to the more commonly used technique of solution els for cell cultures seed aggregates of PSCs onto 2D electrospinning [39, 45, 82]. It opens new possibilities in polystyrene plates where they are treated with chemical the field of engineered electrospun scaffolds. Melt elec- cues to induce differentiation (102). Such plates will not trospinning produces engineered microfibers with a high present or mimic the complex microenvironment of PSCs degree of controllability and repeatability. Dr. Paul Dal- in vivo, and the cells often remodel their architecture to ton and his research group pioneered this technique and adapt to these 2D environments. Therefore, it is necessary they have used melt electrospinning to fabricate scaffolds to construct 3D surfaces that mimic the naturally occurring for a variety of tissue engineering applications [37, 83–91]. environment where PSCs proliferate, grow and differenti- These applications include culturing fibroblasts and engi- ate. neering replacements for damaged tendons. The Willerth Current micro and nanofabrication techniques can be lab in collaboration with Dr. Martin Jun’s research group implemented to generate 2D and 3D structures possessing at Purdue University used a customized melt electrospin- the topography and surface features to support more phys- ning setup to fabricate electrospun scaffolds with novel to- iologically relevant 3D stem cell cultures [103, 104]. Among pographies for promoting the differentiation of PSCs into such fabrication techniques is electrospinning. Therefore, neural tissue [59, 69, 70, 92–96]. Such scaffolds can be de- modifying the surface of common 2D plates with electro- signed and fabricated to meet needs of the consumer by spun fibers opens a new avenue for tissue engineering ap- altering parameters like needle size, collection distance plications that involve the expansion and differentiation and voltage field, which can be tuned to meet specifica- tions provided by a customer [46]. For example, Mohtaram 66 Ë N. K. Mohtaram et al.

Table 1: Examples of Companies that Supply Tissue Culture Plates and their Annual Revenue. (Source: PitchBook Database as of April 25_th, 2017, provided by Ontario Bioscience Innovation Organization – http://www.OBIO.ca).

Company Name Headquarters No of Employees Annual Revenue (US$ m) Johnson & Johnson United States 126,400 71,890.00 Pfizer Inc United States 96,500 52,824.00 F. Hoffmann-La Roche Ltd Switzerland 94,052 52,573.80 Bayer AG Germany 115,200 51,751.65 Novartis AG Switzerland 118,393 49,436.00 Merck & Co Inc United States 68,000 39,807.00 Sanofi France 106,859 38,405.70 GlaxoSmithKline Plc United Kingdom 99,827 37,679.18 Fresenius SE & Co KGaA Germany 232,873 31,064.14 Gilead Sciences Inc United States 9,000 30,390.00 Bayer HealthCare AG Germany 60,700 30,365.06 AbbVie Inc United States 30,000 25,638.00 AstraZeneca Plc United Kingdom 59,700 23,002.00 Amgen Inc United States 19,200 22,991.00 Teva Pharmaceutical Israel 56,960 21,903.00 Industries Ltd Eli Lilly and Company United States 41,975 21,222.10 of PSCs that could eventually be used for therapeutic ap- Various clients in health and education sectors bene- plications as described in the previous section. fit from 3D cell culture technology. For instance, pharmaceutical companies, biotechnology and life-science companies, hospitals, universities, laboratories, and research 6 The Current State of institutes are among the potential customers for 3D cell culture plates and associated projects. Biotechnology com- Commercializing 3D Electrospun panies can generate revenue by licensing their technol- Scaffolds and Associated ogy to one of the current cell culture plate manufacturers. Alternatively, start-up companies can pursue joint ven- Challenges tures with a nanofabrication partner or a cell culture plate producer, generating revenue by selling biomimetic sur- Many biotechnology companies use electrospinning to faces and plates through the sales and marketing network produce biomaterial scaffolds for stem cell research, med- of the plate manufacturer. There are currently numerous ical devices and regenerative medicine as an alternative to well-established 2D cell culture manufacturers. Table 1 using hydrogels. Electrospun scaffolds can provide a 3D lists the most important companies in the field along with niche for stem cells seeded upon or inside. However, the their annual revenue. Most of these companies produce 3D currently available scaffolds are limited to certain appli- cell culture systems based on hydrogels, making it easier cations and have not been readily adopted as the industry to translate promising technologies. Additionally, many standard. Several major challenges must be addressed. For small to medium-size companies are also active in the de- instance, none of the current 3D cell culture systems have sign and manufacture of 3D cell culture plates. However, replaced 2D tissue culture products in terms of the large- none of these companies currently offer biomimetic sur- scale market. Many of the current 3D systems have issues faces suitable for PSC culture and differentiation. in regards to scalability, reproducibility, sensitivity, and compatibility with high-throughput screening [105]. The market for 3D cell culture substrates was $438 million in 2013. This market is expected to grow to about $2.2 billion in 2019 based on a compound annual growth rate (CAGR) of 30.1%. Commercializing Electrospun Scaffolds for Tissue Engineering Applications Ë 67

Table 2: Examples of Companies that Provide Stem Cells and their Annual Revenue. (Source: PitchBook Database as of April 25_th, 2017, provided by Ontario Bioscience Innovation Organization, http://www.OBIO.ca).

Company Name Company Financing Status Growth Primary Industry Group Rate Directlifeglobal Corporation 3.19% Pharmaceuticals and Biotechnology Silene Biotech Accelerator/Incubator Backed 2.73% Healthcare Services Stemmatters Venture Capital-Backed 2.33% Pharmaceuticals and Biotechnology Smart Cells International Venture Capital-Backed 1.82% Pharmaceuticals and Biotechnology Cell Medica Venture Capital-Backed 1.80% Pharmaceuticals and Biotechnology Nobleresearch Corporation 1.75% Pharmaceuticals and Biotechnology Publishers Stem Cell Therapy Corporation 1.72% Pharmaceuticals and Biotechnology Procedure Boston Biomedical Formerly VC-Backed 1.01% Pharmaceuticals and Biotechnology Animal Cell Therapies Angel-Backed 0.94% Pharmaceuticals and Biotechnology Hubrecht Institute Corporation 0.93% Pharmaceuticals and Biotechnology Nexcelom Bioscience Corporation 0.93% Pharmaceuticals and Biotechnology Biobest Laboratories Private Equity-Backed 0.88% Retail Candiolo Cancer Corporation 0.81% Healthcare Devices and Supplies Institute Irccs

Figure 1: Total Capital Invested in the Stem Cell Market in North America. (Source: PitchBook Database as of April 25_th, 2017, provided by Ontario Bioscience Innovation Organization, http://www.OBIO.ca).

7 The Market for 3D Electrospun pography. Table 2 contains examples of companies in- volved with stem cell research along with their growth rate Scaffolds and Stem Cell Related and financing status. Most of the market focuses onstem Products cell research, with less focus on cancer stem cells as ev- idenced by low product availability. Figure 1 shows the rapid growth in the total capital invested in stem cells re- Currently, stem cell research is one of the most common search. In 2016, it reached around $16 billion. This mar- applications of 3D cell cultures, and it has accounted for ket is expected to reach USD $18,329.37 million by 2020 the largest demand for 3D cell culture substrates. For the due to increased spending in research and development. purposes of this review, we will consider electrospun scaf- The methods for developing assays and related tools will folds to provide such a 3D environment due to their to- progress and become more streamlined, and drug devel- 68 Ë N. K. Mohtaram et al.

Figure 2: Total Capital Invested in the Market of Nanofibers in North America. (Source: PitchBook Database as of April 25_th, 2017, provided by Ontario Bioscience Innovation Organization, http://www.OBIO.ca). opers will be able to identify problems with drug candi- nique of electrospinning is quite similar, translating these date leads at earlier stages of development, reducing the technologies to market has been challenging. cost of drug discovery. This issue is one of the most press- In terms of demand for electrospun scaffolds, Figure 2 ing faced by small biopharmaceutical companies as over shows the total capital investment in North American com- 90% of the compounds identified for neurological diseases panies that sell nanofiber-based products, such as Inter- in pre-clinical screens fail during clinical trials [106]. Glob- face Biologics. Innovative, cutting edge, and promising ally, the regenerative medicine market is poised for intense technologies can be firstly designed and implemented in growth as companies turn to regenerative medicine to treat research laboratories. Intellectual property offices at Uni- unmet medical needs. Cell therapy products account for versities and research institutes have their own regula- 76% of regenerative medicine products currently in devel- tions and these offices work extensively with principal in- opment in Europe, Japan and the U.S. The role that 3D cell vestigators, as well as graduate students, to file provisional culture will play in regenerative medicine remains largely patents, protecting their intellectual property. Once these undefined, but can be compared to the testing of biolog- technologies are patented, research labs can perform the ics during process development. If so, the data from the necessary experiments to provide further proof-of-concept research applications will set the stage for later develop- data to support the claims made in the patents. This pro- ment in the field of 3D cell culture substrates pertaining to cess represents the initial steps necessary for commercial- therapeutics. ization of engineered scaffolds. Collaborative projects in tissue engineering have produced numerous promising results as detailed earlier in 8 Translating Technology from this review which eventually support the commercialization of such technology. Patents and their associated Research Laboratories into publications serve as the main conceptual assets of start Start-up Companies up companies working in this field. Once these assests are in place, start up companies can approach local angel investors to further increase the chance of bringing Electrospun scaffolds are easily fabricated in research such products to large scale markets. Research laborato- laboratories. Most of electrospinning commercially avail- ries, hospitals, life science and pharmaceutical companies able electrospinning set-up companies, such as Spray- serve as the potential customers for engineered and cus- base, provide customized systems. Electrospinning setups tom designed scaffolds. Such products are referred to as include a high voltage power supply, a computer numeri- now-products since this field is extremely new and still cal control (CNC) machine, a computer, needles, syringes, faces serious challenges when it comes to successful com- and customized collectors. These components are readily mercialization. These challenges include the scale-up is- available in the commercial marketplace. While the tech- sues, regulatory affairs, and finding potential investigators to develop the products for market. Commercializing Electrospun Scaffolds for Tissue Engineering Applications Ë 69

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