Electrospun Polycaprolactone Scaffolds Research Articles

Mimicking nature: Fabrication of 3D anisotropic electrospun polycaprolactone scaffolds for cartilage tissue engineering applications

There is a growing need to develop strategies capable of engineering the anisotropic cartilaginous fibrous network in vitro and consequently overcome the anatomical and functional restrictions of the standard medical procedures used for cartilage regeneration. In this work, we suggest a fabrication procedure to build 3D anisotropic multi-layered fibrous scaffolds. Polycaprolactone (PCL) was used as bulk material for the different electrospun layers (horizontally, randomly and vertically aligned) that were assembled and then structurally maintained by a biocompatible graphene-oxide-collagen (GO-collagen) microporous network. To validate the resourcefulness of the technique, four PCL-GO-collagen scaffolds with different anisotropic properties were produced and characterized by analysing their depth dependent morphological and mechanical properties.

Electrohydrodynamic Jet 3D Printed Nerve Guide Conduits (NGCs) for Peripheral Nerve Injury Repair.

The prevalence of peripheral nerve injuries resulting in loss of motor function, sensory function, or both, is on the rise. Artificial Nerve Guide Conduits (NGCs) are considered an effective alternative treatment for autologous nerve grafts, which is the current gold-standard for treating peripheral nerve injuries. In this study, Polycaprolactone-based three-dimensional porous NGCs are fabricated using Electrohydrodynamic jet 3D printing (EHD-jetting) for the first time. The main advantage of this technique is that all the scaffold properties, namely fibre diameter, pore size, porosity, and fibre alignment, can be controlled by tuning the process parameters. In addition, EHD-jetting has the advantages of customizability, repeatability, and scalability. Scaffolds with five different pore sizes (125 to 550 μm) and porosities (65 to 88%) are fabricated and the effect of pore size on the mechanical properties is evaluated. In vitro degradation studies are carried out to investigate the degradation profile of the scaffolds and determine the influence of pore size on the degradation rate and mechanical properties at various degradation time points. Scaffolds with a pore size of 125 ± 15 μm meet the requirements of an optimal NGC structure with a porosity greater than 60%, mechanical properties closer to those of the native peripheral nerves, and an optimal degradation rate matching the nerve regeneration rate post-injury. The in vitro neural differentiation studies also corroborate the same results. Cell proliferation was highest in the scaffolds with a pore size of 125 ± 15 μm assessed by the PrestoBlue assay. The Reverse Transcription-Polymerase Chain Reaction (RT-PCR) results involving the three most important genes concerning neural differentiation, namely β3-tubulin, NF-H, and GAP-43, confirm that the scaffolds with a pore size of 125 ± 15 μm have the highest gene expression of all the other pore sizes and also outperform the electrospun Polycaprolactone (PCL) scaffold. The immunocytochemistry results, expressing the two important nerve proteins β3-tubulin and NF200, showed directional alignment of the neurite growth along the fibre direction in EHD-jet 3D printed scaffolds.

Fabrication and In Vitro Characterization of a Tissue Engineered PCL-PLLA Heart Valve

Heart valve diseases are among the leading causes of cardiac failure around the globe. Nearly 90,000 heart valve replacements occur in the USA annually. Currently, available options for heart valve replacement include bioprosthetic and mechanical valves, both of which have severe limitations. Bioprosthetic valves can last for only 10–20 years while patients with mechanical valves always require blood-thinning medications throughout the remainder of the patient’s life. Tissue engineering has emerged as a promising solution for the development of a viable, biocompatible and durable heart valve; however, a human implantable tissue engineered heart valve is yet to be achieved. In this study, a tri-leaflet heart valve structure is developed using electrospun polycaprolactone (PCL) and poly L-lactic acid (PLLA) scaffolds, and a set of in vitro testing protocol has been developed for routine manufacturing of tissue engineered heart valves. Stress-strain curves were obtained for mechanical characterization of different valves. The performances of the developed valves were hemodynamically tested using a pulse duplicator, and an echocardiography machine. Results confirmed the superiority of the PCL-PLLA heart valve compared to pure PCL or pure PLLA. The developed in vitro test protocol involving pulse duplicator and echocardiography tests have enormous potential for routine application in tissue engineering of heart valves.

Optimization and characterization of electrospun polycaprolactone coated with gelatin-silver nanoparticles for wound healing application

Bacterial infection and damage caused by dressing removal are two concerning problems which prolong the healing process in treatment of skin injuries. In this study, plasma treated electrospun polycaprolactone (PCL) scaffold was coated with silver nanoparticles (AgNPs) embedded in gelatin (Gel) by multi-immersion technique to optimize its antibacterial performance and reduce wound-scaffold adhesion. Water interaction test was used to examine the hydrophilization of PCL electrospun fibers after plasma treatment. Scanning Electron Microscopy (SEM) and weight calculation were employed to investigate the morphology and absorptive ability of the GelAg multi-coated PCL membrane (EsPCLGelAg). Antibacterial property of the membrane was evaluated using agar diffusion method against gram positive and gram negative bacteria. Mice model was also used to examine the efficiency of the membrane in healing process and its ability to prevent damage of newly formed tissue when peeling off. SEM results showed that the thickness of GelAg layer on EsPCL membrane increases correspondingly to the number of coating times. In vitro and in vivo data also demonstrated that the greater number of GelAg coating times, the more significant the antibacterial property of the membrane while not sticking to the wound site. These results suggest that multi-coating technique can be applied to optimize the antibacterial property of EsPCLGelAg scaffold and prevent removal-induced damage for wound dressing applications.

Synthesis of a Novel Electrospun Polycaprolactone Scaffold Functionalized with Ibuprofen for Periodontal Regeneration: An In Vitro andIn Vivo Study.

Ibuprofen (IBU) has been shown to improve periodontal treatment outcomes. The aim of this study was to develop a new anti-inflammatory scaffold by functionalizing an electrospun nanofibrous poly-ε-caprolactone membrane with IBU (IBU-PCL) and to evaluate its impact on periodontal inflammation, wound healing and regeneration in vitro and in vivo. IBU-PCL was synthesized through electrospinning. The effects of IBU-PCL on the proliferation and migration of epithelial cells (EC) and fibroblasts (FB) exposed to Porphyromonas gingivlais lipopolysaccharide (Pg-LPS) were evaluated through the AlamarBlue test and scratch assay, respectively. Anti-inflammatory and remodeling properties were investigated through Real time qPCR. Finally, the in vivo efficacy of the IBU-PCL membrane was assessed in an experimental periodontitis mouse model through histomorphometric analysis. The results showed that the anti-inflammatory effects of IBU on gingival cells were effectively amplified using the functionalized membrane. IBU-PCL reduced the proliferation and migration of cells challenged by Pg-LPS, as well as the expression of fibronectin-1, collagen-IV, integrin α3β1 and laminin-5. In vivo, the membranes significantly improved the clinical attachment and IBU-PCL also reduced inflammation-induced bone destruction. These data showed that the IBU-PCL membrane could efficiently and differentially control inflammatory and migratory gingival cell responses and potentially promote periodontal regeneration.

Mesenchymal Stem Cells Derived from Healthy and Diseased Human Gingiva Support Osteogenesis on Electrospun Polycaprolactone Scaffolds.

Periodontitis is a chronic inflammatory disease affecting almost half of the adult US population. Gingiva is an integral part of the periodontium and has recently been identified as a source of adult gingiva-derived mesenchymal stem cells (GMSCs). Given the prevalence of periodontitis, the purpose of this study is to evaluate differences between GMSCs derived from healthy and diseased gingival tissues and explore their potential in bone engineering. Primary clonal cell lines were established from harvested healthy and diseased gingival and characterized for expression of known stem-cell markers and multi-lineage differentiation potential. Finally, they were cultured on electrospun polycaprolactone (PCL) scaffolds and evaluated for attachment, proliferation, and differentiation. Flow cytometry demonstrated cells isolated from healthy and diseased gingiva met the criteria defining mesenchymal stem cells (MSCs). However, GMSCs from diseased tissue showed decreased colony-forming unit efficiency, decreased alkaline phosphatase activity, weaker osteoblast mineralization, and greater propensity to differentiate into adipocytes than their healthy counterparts. When cultured on electrospun PCL scaffolds, GMSCs from both sources showed robust attachment and proliferation over a 7-day period; they exhibited high mineralization as well as strong expression of alkaline phosphatase. Our results show preservation of ‘stemness’ and osteogenic potential of GMSC even in the presence of disease, opening up the possibility of using routinely discarded, diseased gingival tissue as an alternate source of adult MSCs.

Melt Electrospun Bilayered Scaffolds for Tissue Integration of a Suture-Less Inflow Cannula for Rotary Blood Pumps.

Implantation of left ventricular assist devices typically requires cardiopulmonary bypass support, which is associated with postoperative complications. A novel suture-less inflow cannula, which can be implanted without bypass, uses mild myocardial compression to seal the interface, however, this may lead to necrosis of the myocardium. To circumvent this issue, a bilayered scaffold has been developed to promote tissue growth at the interface between cannula and myocardium. The bilayered scaffold consists of a silicone base layer, which mimics the seal, and a melt electrospun polycaprolactone scaffold to serve as a tissue integration layer. Biocompatibility of the bilayered scaffolds was assessed by analyzing cell viability, morphology, and metabolic activity of human foreskin fibroblasts cultured on the scaffolds for up to 14 days. There was no evidence of cytotoxicity and the cells adhered readily to the bilayered scaffolds, revealing a cell morphology characteristic of fibroblasts, in contrast to the low cell adhesion observed on flat silicone sheets. The rate of cell proliferation on the bilayered scaffolds rose over the 14-day period and was significantly greater than cells seeded on the silicone sheets. This study suggests that melt electrospun bilayered scaffolds have the potential to support tissue integration of a suture-less inflow cannula for cardiovascular applications. Furthermore, the method of fabrication described here and the application of bilayered scaffolds could also have potential uses in a diverse range of biomedical applications.

The effect of electrospun polycaprolactone scaffold morphology on human kidney epithelial cells

There is a pressing need for further advancement in tissue engineering of functional organs with a view to providing a more clinically relevant model for drug development and reduce the dependence on organ donation. Polymer-based scaffolds, such as polycaprolactone (PCL), have been highlighted as a potential avenue for tissue engineered kidneys, but there is little investigation down this stream. Focus within kidney tissue engineering has been on two-dimensional cell culture and decellularised tissue. Electrospun polymer scaffolds can be created with a variety of fibre diameters and have shown a great potential in many areas. The variation in morphology of tissue engineering scaffold has been shown to effect the way cells behave and integrate. In this study we examined the cellular response to scaffold architecture of novel electrospun scaffold for kidney tissue engineering. Fibre diameters of 1.10 ± 0.16 μm and 4.49 ± 0.47 μm were used with three distinct scaffold architectures. Traditional random fibres were spun onto a mandrel rotating at 250 rpm, aligned at 1800 rpm with novel cryogenic fibres spun onto a mandrel loaded with dry ice rotating at 250 rpm. Human kidney epithelial cells were grown for 1 and 2 weeks. Fibre morphology had no effect of cell viability in scaffolds with a large fibre diameter but significant differences were seen in smaller fibres. Fibre diameter had a significant effect in aligned and cryogenic scaffold. Imaging detailed the differences in cell attachment due to scaffold differences. These results show that architecture of the scaffold has a profound effect on kidney cells; whether that is effects of fibre diameter on the cell attachment and viability or the effect of fibre arrangement on the distribution of cells and their alignment with fibres. Results demonstrate that PCL scaffolds have the capability to maintain kidney cells life and should be investigated further as a potential scaffold in kidney tissue engineering.

A comparison study between electrospun polycaprolactone and piezoelectric poly(3-hydroxybutyrate-co-3-hydroxyvalerate) scaffolds for bone tissue engineering

In this study, bone scaffolds composed of polycaprolactone (PCL), piezoelectric poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and a combination of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and silicate containing hydroxyapatite (PHBV-SiHA) were successfully fabricated by a conventional electrospinning process. The morphological, chemical, wetting and biological properties of the scaffolds were examined. All fabricated scaffolds are composed of randomly oriented fibres with diameters from 800nm to 12μm. Fibre size increased with the addition of SiHA to PHBV scaffolds. Moreover, fibre surface roughness in the case of hybrid scaffolds was also increased. XRD, FTIR and Raman spectroscopy were used to analyse the chemical composition of the scaffolds, and contact angle measurements were performed to reveal the wetting behaviour of the synthesized materials. To determine the influence of the piezoelectric nature of PHBV in combination with SiHA nanoparticles on cell attachment and proliferation, PCL (non-piezoelectric), pure PHBV, and PHBV-SiHA scaffolds were seeded with human mesenchymal stem cells (hMSCs). In vitro study on hMSC adhesion, viability, spreading and osteogenic differentiation showed that the PHBV-SiHA scaffolds had the largest adhesion and differentiation abilities compared with other scaffolds. Moreover, the piezoelectric PHBV scaffolds have demonstrated better calcium deposition potential compared with non-piezoelectric PCL. The results of the study revealed pronounced advantages of hybrid PHBV-SiHA scaffolds to be used in bone tissue engineering.

A simple rocker-induced mechanical stimulus upregulates mineralization by human osteoprogenitor cells in fibrous scaffolds.

Biodegradable electrospun polycaprolactone scaffolds can be used to support bone‐forming cells and could fill a thin bony defect, such as in cleft palate. Oscillatory fluid flow has been shown to stimulate bone production in human progenitor cells in monolayer culture. The aim of this study was to examine whether bone matrix production by primary human mesenchymal stem cells from bone marrow or jaw periosteal tissue could be stimulated using oscillatory fluid flow supplied by a standard see‐saw rocker. This was investigated for cells in two‐dimensional culture and within electrospun polycaprolactone scaffolds. From day 4 of culture onwards, samples were rocked at 45 cycles/min for 1 h/day, 5 days/week (rocking group). Cell viability, calcium deposition, collagen production, alkaline phosphatase activity and vascular endothelial growth factor secretion were evaluated to assess the ability of the cells to undergo bone differentiation and induce vascularisation. Both cell types produced more mineralized tissue when subjected to rocking and supplemented with dexamethasone. Mesenchymal progenitors and primary human mesenchymal stem cells from bone marrow in three‐dimensional scaffolds upregulated mineral deposition after rocking culture as assessed by micro‐computed tomography and alizarin red staining. Interestingly, vascular endothelial growth factor secretion, which has previously been shown to be mechanically sensitive, was not altered by rocking in this system and was inhibited by dexamethasone. Rocker culture may be a cost effective, simple pretreatment for bone tissue engineering for small defects such as cleft palate.

The effect of ozone gas sterilization on the properties and cell compatibility of electrospun polycaprolactone scaffolds

The growing area of tissue engineering has the potential to alleviate the shortage of tissues and organs for transplantation, and electrospun biomaterial scaffolds are extremely promising devices for translating engineered tissues into a clinical setting. However, to be utilized in this capacity, these medical devices need to be sterile. Traditional methods of sterilization are not always suitable for biomaterials, especially as many commonly used biomedical polymers are sensitive to chemical-, thermal- or radiation-induced damage. Therefore, the objective of this study was to evaluate the suitability of ozone gas for sterilizing electrospun scaffolds of polycaprolactone (PCL), a polymer widely utilized in tissue engineering and regenerative medicine applications, by evaluating if scaffolds composed of either nanofibres or microfibres were differently affected by the sterilization method. The sterility, morphology, mechanical properties, physicochemical properties, and response of cells to nanofibrous and microfibrous PCL scaffolds were assessed after ozone gas sterilization. The sterilization process successfully sterilized the scaffolds and preserved most of their initial attributes, except for mechanical properties. However, although the scaffolds became weaker after sterilization, they were still robust enough to use as tissue engineering scaffolds and this treatment increased the proliferation of L929 fibroblasts while maintaining cell viability, suggesting that ozone gas treatment may be a suitable technique for the sterilization of polymer scaffolds which are significantly damaged by other methods.

Evaluation of Stem Cells’ Growth on Electrospun Polycaprolactone (PCL) Scaffolds Used for Soft Tissue Applications

This study focuses on the preparation of a synthetic tissue from a biodegradable polymer that can be used for soft tissue applications using electrospinning technique. Biodegradable thermoplastic polymer which is polycaprolactone (PCL) used for making electrospun scaffolds in three concentrations (10, 15 and 20%) Weight/Volume PCL. The results revealed the increasing in fiber diameter with increasing PCL concentration in the prepared solutions for electrospinning. Then the growth of horse adipose derived mesenchymal stem cells was evaluated in vitro over these prepared scaffolds for 21 days with and without soaking in fetal bovine serum to study cells’ growth rate and proliferation over the scaffold surface. The Scanning electron microscope (SEM) analysis showed high growth rates for stem cells on these prepared scaffolds especially 15% w/v PCL which supported stem cells growth even when it was not soaked in serum. The histological analysis revealed that the suitable structure for cells spread and penetration resulted in 15 and 20% PCL scaffolds. In conclusions, these prepared scaffolds could be a candidate for use in soft tissues repair and thus for regenerative medicine application, because they highly supported stem cells growth.

In-vivo characterization of a 3D hybrid scaffold based on PCL/decellularized aorta for tracheal tissue engineering

IntroductionAs common treatments for long tracheal stenosis are associated with several limitations, tracheal tissue engineering is considered as an alternative treatment. Aim of studyThis study aimed at preparing a hybrid scaffold, based on biologic and synthetic materials for tracheal tissue engineering. Materials and methodsThree electrospun polycaprolactone (PCL) scaffolds, namely E1 (pure PCL), E2 (collagen-coated PCL) and E3 (PCL blended with collagen) were prepared. Allogeneic aorta was harvested and decellularized. A biodegradable PCL stent was fabricated and inserted into the aorta to prevent its collapse. ResultScaffold characterization results revealed that the 2-h swelling ratio of E2 was significantly higher than those of E1 and E3. In the first 3months, E2 and E3 exhibited almost equal degradabilities (significantly higher than that of E1). Moreover, tensile strengths of all samples were comparable with those of human trachea. Using rabbit's adipose-derived mesenchymal stem cells (AMSCs) and primary chondrocytes, E3 exhibited the highest levels of GAG release within 21days as well as collagen II and aggrecan expression.Fot the next step, AMSC-chondrocyte co-culture seeded scaffold was sutured to the acellular aorta, implanted into rabbits' muscle, and finally harvested after 4weeks of follow up. ConclusionHarvested structures were totally viable due to the angiogenesis created by the muscle. H&E and alcian blue staining results revealed the presence of chondrocytes in the structure and GAG in the produced extracellular matrix.Since tracheal replacement using biologic and synthetic scaffolds usually results in tracheal collapse or granulation formation, a hybrid construct may provide the required rigidity and biocompatibility for the substitute.

Examinations of a new long-term degradable electrospun polycaprolactone scaffold in three rat abdominal wall models.

Alternative approaches to reinforce native tissue in reconstructive surgery for pelvic organ prolapse are warranted. Tissue engineering combines the use of a scaffold with the regenerative potential of stem cells and is a promising new concept in urogynecology. Our objective was to evaluate whether a newly developed long-term degradable polycaprolactone scaffold could provide biomechanical reinforcement and function as a scaffold for autologous muscle fiber fragments. We performed a study with three different rat abdominal wall models where the scaffold with or without muscle fiber fragments was placed (1) subcutaneously (minimal load), (2) in a partial defect (partial load), and (3) in a full-thickness defect (heavy load). After 8 weeks, no animals had developed hernia, and the scaffold provided biomechanical reinforcement, even in the models where it was subjected to heavy load. The scaffold was not yet degraded but showed increased thickness in all groups. Histologically, we found a massive foreign body response with numerous large giant cells intermingled with the fibers of the scaffold. Cells from added muscle fiber fragments could not be traced by PKH26 fluorescence or desmin staining. Taken together, the long-term degradable polycaprolactone scaffold provided biomechanical reinforcement by inducing a marked foreign-body response and attracting numerous inflammatory cells to form a strong neo-tissue construct. However, cells from the muscle fiber fragments did not survive in this milieu. Properties of the new neo-tissue construct must be evaluated at the time of full degradation of the scaffold before its possible clinical value in pelvic organ prolapse surgery can be evaluated.

Electrospun polycaprolactone (PCL) scaffolds embedded with europium hydroxide nanorods (EHNs) with enhanced vascularization and cell proliferation for tissue engineering applications.

Electrospun polycaprolactone (PCL) tissue engineering scaffolds have been developed and used for a wide range of tissue engineering applications, where successful incorporation and conservation of the therapeutic activity of the embedded nanoparticles into scaffolds is critically needed for effective tissue engineering. Incorporation of pro-angiogenic nanomaterials to promote vascularization is a novel approach. Our group has well-demonstrated the potent pro-angiogenic properties of europium hydroxide nanorods (EHNs) using in vitro and in vivo systems. In the present study, electrospun PCL tissue engineering scaffolds containing EHNs were fabricated and characterized for various morphological and physico-chemical properties. Furthermore, biological studies showed enhanced cell growth and a greater density of endothelial cells grown on the scaffolds incorporated with EHNs (PCL-EHNs). The PCL-EHNs also exhibited good hemo-compatibility towards blood cells. Fluorescence microscopy and SEM observations showed good endothelial cell adhesion over these scaffolds. The PCL-EHNs demonstrated augmented growth of blood vessels in an in vivo chick embryo angiogenesis model. Furthermore, protein expression studies illustrated promoted angiogenesis of HUVECs on scaffolds in a VEGFR2/Akt mediated signaling cascade. Together, the above observations strongly suggest potent applications of EHN-incorporated PCL scaffolds in promoting angiogenesis/vascularization and their effective use in tissue engineering and vascular disease therapy.

Biomineralization of electrospun polycaprolactone-guided bone regeneration membrane

To evaluate the biomineralization of the tissue-engineering electrospun polycaprolactone (PCL) scaffold and its potential use for guided bone regeneration (GBR) membranes. PCL ultrafinefiber scaffolds were fabricated by electrospinning and then immersed in supersaturated calcification solution (SCS) for biomineralization investigation. The electrospun PCL scaffolds and the calcium phosphate coating were identified by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Water-contact angles were also measured to evaluate the hydrophilicity of the modified surface. The biocompatibility of the composite was investigated by culturing osteoblasts on the scaffolds. Cell behavior was observed by SEM. The electrospun PCL scaffold was composed of ultrafine fibers and well-interconnected pores. The deposits on the fibers grew in number and size as the biomineralization time increased. Then, the covering of the whole PCL film was identified as dicalcium phosphate dehydrate and apatite. Good cell attachment and proliferation behavior were observed on the membranes. The quick apatite formation on the surface of the PCL electrospun scaffold indicated that SCS biomineralization may be an effective approach for obtaining PCL/calcium phosphate composites. The cellular biocompatibility of the composite scaffold was preliminarily confirmed by the in vitro culture of osteoblasts on the scaffold. As such, the composite scaffold is a promising biomimetic extracellular matrix biomaterial for bone tissue engineering and GBR membranes.

Indirect coculture of stem cells with fetal chondrons using PCL electrospun nanofiber scaffolds

In vitro coculture system provides a powerful tool for tissue engineering. In this study, we evaluated the gene expressions of human adipose-derived stem cells (ASCs) on polycaprolactone (PCL) scaffold in coculture model with fetal chondrons. Electrospun PCL scaffolds (900 nm fiber diameter) were created and human infrapatellar fat pad-adipose-derived stem cells (IPFP-ASCs) were seeded on these scaffolds. Scanning electron microscopy (SEM) showed attachment of human IPFP–ASCs to scaffold. IPFP-ASCs on scaffolds were cocultured with fetal chondrons in transwell. Gene expressions were investigated using real-time polymerase chain reaction (real-time PCR). In comparison with control group, the expression level of collagen type 2 and aggrecan were significantly decreased but Indian Hedgehog(IHH) significantly increased (P < 0.05).These findings may interpreted that IPFP-ASCs seeded on PCL scaffold, in cocultures with fetal chondrons are tending toward osteogenesis rather than chondrogenesis.

Androgen actions in mouse wound healing: Minimal in vivo effects of local antiandrogen delivery

The aims of this work were to define the role of androgens in female wound healing and to develop and characterize a novel wound dressing with antiandrogens. Androgens retard wound healing in males, but their role in female wound healing has not been established. To understand androgen receptor (AR)-mediated androgen actions in male and female wound healing, we utilized the global AR knockout (ARKO) mouse model, with a mutated AR deleting the second zinc finger to disrupt DNA binding and transcriptional activation. AR inactivation enhanced wound healing rate in males by increasing re-epithelialization and collagen deposition even when wound contraction was eliminated. Cell proliferation and migration in ARKO male fibroblasts was significantly increased compared with wild-type (WT) fibroblasts. However, ARKO females showed a similar healing rate compared to WT females. To exploit local antiandrogen effects in wound healing, while minimizing off-target systemic effects, we developed a novel electrospun polycaprolactone (PCL) scaffold wound dressing material for sustained local antiandrogen delivery. Using the antiandrogen hydroxyl flutamide (HF) at 1, 5, and 10 mg/mL in PCL scaffolds, controlled HF delivery over 21 days significantly enhanced in vitro cell proliferation of human dermal fibroblasts and human keratinocytes. HF-PCL scaffolds also promoted in vivo wound healing in mice compared with open wounds but not to PCL scaffolds.

Plasma Polymer and Biomolecule Modification of 3D Scaffolds for Tissue Engineering

Plasma polymerization was used to coat a melt electrospun polycaprolactone scaffold to improve cell attachment and organization. Plasma polymerization was performed using an amine containing monomer, allylamine, which then allowed for the subsequent immobilization of biomolecules, i.e., heparin and fibroblast growth factor-2. The stability of the plasma-polymerized amine-coating was demonstrated by X-ray photoelectron spectroscopy analysis and imaging time-of-flight secondary ion mass spectrometry revealed that a uniform plasma amine-coating was deposited throughout the scaffold. Based upon comparison with controls, it was evident that the combination scaffold aided cell ingress and the formation of distinct fibroblast and keratinocyte layers.

Cell Adhesion on Polycaprolactone Modified by Plasma Treatment

We have investigated the influence of various plasma treatments of electrospun polycaprolactone (PCL) scaffolds on the adhesion and proliferation of human umbilical endothelial cells (HUVEC). The PCL scaffolds were treated in plasmas created in O2, NH3or SO2gas at identical conditions. Surface functionalization of plasma-treated samples was determined using X-ray photoelectron spectroscopy. Cell adhesion and morphology were investigated by scanning electron microscopy and the influence of plasma treatment on cell adhesion and viability was evaluated with cell viability assay (MTT assay). The results showed the highest metabolic activity of HUVEC on PCL samples treated with O2and NH3plasma. Accordingly, the cells reflected the best adhesion and morphology on O2and NH3plasma-treated PCL samples already at 3 h. Moreover, treatment with O2and NH3plasma even stimulated endothelial cell proliferation on PCL surfaces by 60% as measured at 24 h, showing significant improvement in endothelialization of this material. Contrarily, SO2plasma appeared to be less promising in comparison with O2and NH3plasma; however, it was still better than without any plasma treatment. Thus, our results importantly contribute to the biocompatibility improvement of the PCL polymer, commonly used for scaffolds in tissue engineering.