Application of low loading of collagen in electrospun poly[(l‐lactide)‐co‐(ε‐caprolactone)] nanofibrous scaffolds to promote cellular biocompatibility

Electrospinning of various polymers has been used to produce nanofibrous scaffolds that mimic the extracellular matrix and support cell attachment for the potential repair and engineering of nerve tissue. In the study reported here, an electrospun copolymer of l ‐lactide and ε‐caprolactone (67:33 mol%) resulted in a nanofibrous scaffold with average fibre diameter and pore size of 476 ± 88 and 253 ± 17 nm, respectively. Blending with low loadings of collagen (<2.5% w/w) significantly reduced the average diameter and pore size. The uniformity of fibre diameter distributions was supported with increasing collagen loadings. The nanofibrous scaffolds significantly promoted the attachment and proliferation of olfactory ensheathing cells compared to cells exhibiting asynchronous growth. Furthermore, analysis of cell health through mitochondrial activity, membrane leakage, cell cycle progression and apoptotic indices showed that the nanofibrous membranes promoted cell vigour, reducing necrosis. The study suggests that the use of more cost‐effective, low loadings of collagen supports morphological changes in electrospun poly[(l ‐lactide)‐co‐(ε‐caprolactone)] nanofibrous scaffolds, which also support attachment and proliferation of olfactory ensheathing cells while promoting cell health. The results here support further investigation of the electrospinning of these polymer blends as conduits for nerve repair. © 2013 Society of Chemical Industry     

Herbally derived polymeric nanofibrous scaffolds for bone tissue regeneration

Hydroxyapatite (HA), the bone mineral and Cissus quadrangularis (CQ), a medicinal plant with osteogenic activity, are attaining increasing interest as a potential therapeutic agent for enhanced bone tissue regeneration. In the present study a synergistic effect of these two agents were analyzed by fabricating PCL‐CQ‐HA nanofibrous scaffolds by electrospinning and compared with PCL‐CQ and PCL (control) nanofibrous scaffolds. Morphology, composition, hydrophilicity, and mechanical properties of the electrospun PCL, PCL‐CQ, PCL‐CQ‐HA nanofibrous scaffolds were examined by Field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), Contact angle and Tensile tests, respectively. The response of human foetal osteoblast cells on these scaffolds were evaluated using MTS assay, alkaline phosphatase activity, alizarin red staining, and osteocalcin expression for bone tissue regeneration. While the observed cellular response to both groups of scaffolds was better than for the control PCL scaffold, the PCL‐CQ‐HA nanofibrous scaffolds provided the most favorable substrate for cell proliferation and mineralization. The results showed that PCL‐CQ‐HA nanofibrous scaffolds had appropriate surface roughness for the osteoblast adhesion, proliferation, and mineralization comparing with other scaffolds. The observed investigation of physicochemical and biological properties suggests that the CQ‐HA loaded PCL nanofibrous scaffolds serve as a potential biocomposite material for bone tissue engineering. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39835.     

Development of Polyvinyl Alcohol Fibrous Biodegradable Scaffolds for Nerve Tissue Engineering Applications: In Vitro Study

In this study, polyvinyl alcohol (PVA) fibers were modified through an effective cross linking method. Adequate porosity and surface area are widely recognized as important parameters in the design of scaffolds for tissue engineering and therefore measurement of porosity is very important. Herein, porosity measurement of various surface layers of scaffold was done through a new method, and image analysis was used for this purpose. Scanning electron microscopy micrographs of nanofibrous scaffolds were converted to binary images using different thresholds and porosity of scaffold was measured in various layers. In addition, for ascertaining of cross linking of the PVA nanofibrous scaffolds, Fourier transform infrared spectroscopy analysis was employed. Also, the in vitro biodegradability of the nanofibrous scaffold was evaluated. The PVA crosslinked nanofibrous scaffold was found to exhibit the most balanced properties to meet all the required specifications for nerve tissue and was used for in vitro culture of nerve stem cells (PC12 cells). Finally, the results of the swelling behavior of the samples revealed that the cross linked PVA scaffold has a strong swelling about 450%.     

Enhanced chondrogenic differentiation of human bone marrow mesenchymal stem cells on PCL/PLGA electrospun with different alignments and compositions

The simultaneous effect of electrospun scaffold alignment and polymer composition on chondrogenic differentiation of human bone marrow mesenchymal stem cells (hBMMSC) is investigated. Aligned and randomly oriented polycaprolactone/poly(lactic-co-glycolic acid) (PLGA) hybrid electrospun scaffolds with two different ratios are fabricated by electrospinning. It is found that aligned nanofibrous scaffolds support higher chondrogenic differentiation of hBMMSCs compared to random ones. The aligned scaffolds show a higher expression level of chondrogenic markers such as type II collagen and aggrecan. It is concluded that the aligned nanofibrous scaffold with higher PLGA ratio could significantly enhance hBMMSC proliferation and differentiation to chondrocytes.     

Three-dimensional silk impregnated HAp/PHBV nanofibrous scaffolds for bone regeneration

Three-dimensional silk fibroin impregnated poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibrous scaffolds with or without hydroxyapatite (HAp) were prepared by wet-electrospinning method followed by freeze-drying. Scaffolds with cotton wool-like structure have the average fiber diameter of 450–850?nm with 80–85% porosity. In-vitro cell culture tests using MG-63 osteosarcoma human cells revealed improved cell viability, alkaline phosphatase (ALP) activity and total cellular protein amount on the silk impregnated scaffolds compared to PHBV and HAp/PHBV scaffolds after 10 days of cell culture. Immunohistochemical analyses on the silk impregnated scaffolds showed that HAp triggered cell penetration and type I collagen production. Besides, HAp mineralization tendency increased with a decrease in percent crystallinity of the scaffolds comprising HAp and silk after 4 weeks of incubation in simulated body fluid. Consequently, cotton wool-like HAp/PHBV-SF scaffold would be a promising candidate as a bone-filling material for tissue regeneration.     

Preparation and characterization of polyhydroxybutyrate‐co‐hydroxyvalerate/silk fibroin nanofibrous scaffolds for skin tissue engineering

Nanofibrous scaffolds were obtained by co‐electrospinning poly (3‐hydroxybuty‐rate‐co‐3‐hydroxyvalerate) (PHBV) and fibroin regenerated from silk in different proportions using 1,1,1,3,3,3‐hexafluoro‐2‐isopropanol (HFIP) as solvent. Field emission scanning electron microscope (FESEM) investigation showed that the fiber diameters of the nanofibrous scaffolds ranged from 190 to 460 nm. X‐ray diffraction (XRD) and Fourier transform infrared spectroscopy analysis (FT‐IR) showed that the main structure of silk fibroin (SF) in the nanofibrous scaffold was β‐sheet. Compared to the PHBV nanofibrous scaffold, the surface hydrophilicity and water‐uptake capability of the PHBV/SF nanofibrous scaffold with 50/50 were improved. The results of cell adhesion experiment showed that the fibroblasts adhered more to the PHBV/SF nanofibrous scaffold with 50/50 than the pure PHBV nanofibrous scaffold. The proliferation of fibroblast on the PHBV/SF nanofibrous scaffold with 50/50 was higher than that on the pure PHBV nanofibrous scaffold. Our results indicated that the PHBV/SF nanofibrous scaffold with 50/50 may be a better candidate for biomedical applications such as skin tissue engineering and wound dressing. POLYM. ENG. SCI., 55:907–916, 2015. © 2014 Society of Plastics Engineers     

Preparation and characterization of Calendula officinalis-loaded PCL/gum arabic nanocomposite scaffolds for wound healing applications

Medicinal plants such as Calendula officinalis (C. officinalis) are commonly used for skin wounds’ treatment. On the other hand, gum arabic (GA) has a lot of potential for use in wound healing because of its unique physio-chemical properties. Wound healing activity of gum arabic (GA) and Calendula officinalis (C. officinalis) along with good mechanical properties of poly (ε-caprolactone) (PCL) can produce a suitable nanofibrous scaffold for skin tissue engineering as well as wound dressing application. In this study, PCL/C. officinalis/GA nanofibrous scaffolds with diameter distribution in the range of 85–290 nm were prepared via electrospinning. Characteristics of the nanofibrous scaffolds, i.e., morphology, scaffold compounds, porosity, mechanical and antibacterial properties, hydrophilicity and degradability in phosphate buffer saline (PBS) were investigated. Cell viability and proliferation of scaffolds were evaluated by MTT [3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay. Results indicated that hydrophilicity of the PCL/C. officinalis/GA scaffolds was higher than the PCL scaffold. The tensile strength and elongation of the PCL/C. officinalis/GA scaffolds were in the range of 2.13–4.41 MPa and 26.37–74.37%, respectively, which are very suitable for skin tissue engineering. The porosity of the scaffolds was higher than 60% and was appropriate for the proliferation of fibroblast cells. The nanocomposite scaffold also showed suitable degradability and antimicrobial activity. Moreover, cell culture indicated that GA and C. officinalis promoted cell attachment and proliferation. It can be concluded that the nanofibrous calendula-loaded PCL/GA scaffolds are well suited for regenerating skin.

     

Nanofibrous scaffold prepared by electrospinning of poly(vinyl alcohol)/gelatin aqueous solutions

A series of nanofibrous scaffolds were prepared by electrospinning of poly(vinyl alcohol) (PVA)/gelatin aqueous solution. PVA and gelatin was dissolved in pure water and blended in full range, then being electrospun to prepared nanofibers, followed by being crosslinked with glutaraldehyde vapor and heat treatment to form nanofibrous scaffold. Field emission scanning electron microscope (FESEM) images of the nanofibers manifested that the fiber average diameters decreased from 290 to 90 nm with the increasing of gelatin. In vitro degradation rates of the nanofibers were also correlated with the composition and physical properties of electrospinning solutions. Cytocompatibility of the scaffolds was evaluated by cells morphology and MTT assay. The FESEM images revealed that NIH 3T3 fibroblasts spread and elongated actively on the scaffolds with spindle‐like and star‐type shape. The results of cell attachment and proliferation on the nanofibrous scaffolds suggested that the cytotoxicity of all samples are grade 1 or grade 0, indicating that the material had sound biosafety as biomaterials. Compared with pure PVA and gelatin scaffolds, the hybrid ones possess improved biocompatibility and controllability. These results indicate that the PVA/gelatin nanofibrous have potential as skin scaffolds or wound dressing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Modification of PCL Electrospun Nanofibrous Mat With Calendula officinalis Extract for Improved Interaction With Cells

Nanofibers have improved the performance of biomaterials, and could be considered effective. In this study, poly(?-caprolactone) (PCL)/Calendula officinalis nanofibers were well designed by different analyses. FTIR structural analysis showed the presence of functional groups on the nanofibrous surfaces. The SEM images showed the average size of nanofibers increased with increase in Calendula concentration. The 100° difference was obtained in the contact angle analysis with changes in Calendula concentration; however, tensile strength decreased for the Poly(?-caprolactone)/Calendula officinalis nanofibrous mat compared those unmodified ones. Cellular investigation showed better adhesion, proliferation, and tenocyte cells growth on poly(?-caprolactone)/Calendula officinalis nanofibrous samples than pure PCL nanofibrous mat. The bioavailability of PCL fibers with Calendula officinalis extract was found to be identical to that of PCL fibers, indicating that Calendula officinalis extract is a suitable material for enhancing the biocompatibility of tissue engineering scaffolds.     

Development of poly (L-lactide-co-caprolactone) multichannel nerve conduit with aligned electrospun nanofibers for Schwann cell proliferation

Biomaterials are playing a significant role in understanding and promoting the plasticity and repair of the nervous system. Biomimetic nanofibrous scaffolds mimicking important features of the native extracellular matrix provide a promising strategy to restore functions or achieve favorable responses for tissue regeneration and autograft nerve conduit is one of the most promising nerve regeneration strategies. The present study is based on novel fabrication method by using a special collector for 3D multichannel nerve conduit, longitudinally oriented with aligned electrospun nanofibers. The conduit contained a high number of channels (varying from 7 to 19) and each channel showed a separate morphology. Nerve channels were fabricated with the varying length ranging from 4 to 9 cm and total diameter ranging from 2200 ± 40 µm to 3951 ± 196 µm, while the channel diameter ranging from 350 ± 86 µm to 780 ± 20 µm. It has been clearly shown that the average porosity of nerve conduits has reached almost 89%. In this study, we optimized the parameters to control the structural stability, including the size and the number of channels in the nerve conduit. We also checked in vitro cell biocompatibility of multichannel nerve conduit and demonstrated that Schwann cells have the tendency to grow along the direction of nanofibers and high cell growth was observed in high number of channels compared to low number of channels. These results elaborated the potential use of this biocompatible multichannel nerve conduit for further in vivo testing.     

Fabrication of a Nanofibrous Scaffold for the In Vitro Culture of Cardiac Progenitor Cells for Myocardial Regeneration

In this study, random Poly (?-caprolactone) (PCL):Poly glycolic acid (PGA) nanofibrous scaffold with various PCL:PGA compositions were fabricated by electrospinning method. The nanofibrous scaffolds were characterized by SEM, contact angle measurement, ATR-FTIR, and tensile measurements. The results showed that with the increase of the concentration of PGA in spinning blend solution, the average diameter of nanofibers, hydrophilicity, and mechanical properties of the nanofibrous scaffolds increased. An in vitro degradation study of PCL:PGA nanofibers were conducted in phosphate-buffered saline, pH 7.2. The experiments confirm that increasing of PGA provides faster degradation rate in blended nanofibers. To assay the biocompatibility and cell behavior on the nanofibrous scaffolds, cell attachment and spreading of cardiac progenitor cells seeded on the scaffolds were studied. The results indicate that among electrospun nanofibrous scaffolds, the most appropriate candidate for myocardial tissue engineering scaffolds is PCL:PGA (65:35).     

Nanohydroxyapatite-coated hydroxyethyl cellulose/poly (vinyl) alcohol electrospun scaffolds and their cellular response

The present study focused on the preparation of nanohydroxyapatite (nHA)-coated hydroxyethyl cellulose/polyvinyl alcohol (HEC/PVA) nanofibrous scaffolds for bone tissue engineering application. The electrospun HEC/PVA scaffolds were mineralized via alternate soaking process. FESEM revealed that the nHA was formed uniformly over the nanofibers. The nHA mineralization enhanced the tensile strength and reduced the elongation at breakage of scaffolds. The wettability of the nanofibrous scaffolds was significantly improved. The in vitro biocompatibility of scaffolds was evaluated with human osteosarcoma cells. nHA-coated scaffolds had a favorable effect on the proliferation and differentiation of osteosarcoma cell and could be a potential candidate for bone regeneration.     

Embryonic Stem Cell Differentiation to Cardiomyocytes on Nanostructured Scaffolds for Myocardial Tissue Regeneration

With recent advances in developmental and stem cell biology, the application of stem cells in tissue engineering has received great attention and designing of suitable scaffolds to support cell growth, differentiation, and functional tissue organization are advancing toward effective tissue regeneration. Regeneration of the infarct myocardium after myocardial infarction (MI), which is caused by the abrupt occlusion of one or more of the coronary arteries in the heart is one of the most demanding aspects in tissue engineering. Embryonic stem cells (ESCs) can differentiate into many cell types and has been considered as a cell source for cardiac regeneration. In this regard, nanofibrous scaffolds received great attention in tissue engineering field due to their similarity in morphology to native extracellular matrix (ECM) and various scaffolds have been studied as cardiac patches over the previous years. In this study poly (ε-caprolactone) (PCL)/gelatin nanofibrous scaffolds were fabricated by electrospinning and embroyonic bodies (EBs) were formed using ESCs seeded on the nanofibrous scaffolds. SEM images revealed cell outgrowth from EBs and the spreading of cells over the nanofibrous scaffolds were observed. Immunocytochemistry results showed the cellular expression of cardiac proteins, namely α-actinin and connexin 43 on the nanofibrous scaffolds indicating the differentiation of EBs to cardiomyocytes. Results of our study showed that PCL/gelatin nanofibrous scaffolds can act as a promising substrate for differentiation of EBs to cardiomyocytes and could be applied for cardiac tissue engineering.     

Fabrication of PLA/PEG/MWCNT electrospun nanofibrous scaffolds for anticancer drug delivery

In the present study, polylactic acid (PLA)/polyethylene glycol (PEG)/multiwalled carbon nanotube (MWCNT) electrospun nanofibrous scaffolds were prepared via electrospinning process and their applications for the anticancer drug delivery system were investigated. A response surface methodology based on Box–Behnken design (BBD) was used to evaluate the effect of key parameters of electrospinning process including solution concentration, feeding rate, tip–collector distance (TCD) and applied voltage on the morphology of PLA/PEG/MWCNT nanofibrous scaffolds. In optimum conditions (concentration of 8.15%, feeding rate of 0.2 mL/h, voltage of 18.50 kV and TCD of 13.0 cm), the minimum experimental fiber diameter was found to be 225 nm which was in good agreement with the predicted value by the BBD analysis (228 nm). In vitro drug release study of doxorubicin (DOX)‐loaded nanofibrous scaffolds, higher drug content induced an extended release of drug. Also, drug release rate was not dependent on drug/polymer ratio in different electrospun nanofibrous formulations. The equation of M_t = c₀ + kt^0.5was used to describe the kinetic data of DOX release from electrospun nanofibers. The cell viability of DOX‐loaded nanofibrous scaffolds was evaluated using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide, a tetrazole assay on lung cancer A549 cell lines. We propose that DOX‐incorporated PLA/PEG/MWCNT nanofibrous scaffold could be used as a superior candidate for antitumor drug delivery. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41286.     

Nanostructured Guidance for Peripheral Nerve Injuries: A Review with a Perspective in the Oral and Maxillofacial Area

Injury to peripheral nerves can occur as a result of various surgical procedures, including oral and maxillofacial surgery. In the case of nerve transaction, the gold standard treatment is the end-to-end reconnection of the two nerve stumps. When it cannot be performed, the actual strategies consist of the positioning of a nerve graft between the two stumps. Guided nerve regeneration using nano-structured scaffolds is a promising strategy to promote axon regeneration. Biodegradable electrospun conduits composed of aligned nanofibers is a new class of devices used to improve neurite extension and axon outgrowth. Self assembled peptide nanofibrous scaffolds (SAPNSs) demonstrated promising results in animal models for central nervous system injuries, and, more recently, for peripheral nerve injury. Aims of this work are (1) to review electrospun and self-assembled nanofibrous scaffolds use in vitro and in vivo for peripheral nerve regeneration; and (2) its application in peripheral nerve injuries treatment. The review focused on nanofibrous scaffolds with a diameter of less than approximately 250 nm. The conjugation in a nano scale of a natural bioactive factor with a resorbable synthetic or natural material may represent the best compromise providing both biological and mechanical cues for guided nerve regeneration. Injured peripheral nerves, such as trigeminal and facial, may benefit from these treatments.     

Preparation and characterization of nanohydroxyapatite strengthening nanofibrous poly(L‐lactide) scaffold for bone tissue engineering

A biomimetic nanofibrous poly(L ‐lactide) scaffold strengthened by nanohydroxyapatite particles was fabricated via a thermally induced phase separation technique. Scanning electron microscopy results showed that nanohydroxyapatite particles uniformly dispersed in the nanofibrous poly(L ‐lactide) scaffold (50–500 nm in fiber diameter) with slight aggregation at a high nHA content, but showed no influence on the interconnected macroporous and nanofibrous structure of the scaffold. The nanofibrous poly(L ‐lactide) scaffold presented a specific surface area of 34.06 m² g^?1, which was much higher than that of 2.79 m² g^?1 for the poly(L ‐lactide) scaffold with platelet structure. Moreover, the specific surface area of the nanofibrous scaffold was further enhanced by incorporating nanohydroxyapatite particles. With increasing the nanohydroxyapatite content, the compressive modulus and amount of bovine serum albumin adsorbed on the surface of the nanofibrous composite scaffold were markedly improved, as opposed to the decreased crystallinity. In comparison to poly(L ‐lactide) scaffold, both the nanofibrous poly(L ‐lactide) and poly(L ‐lactide)/nanohydroxyapatite scaffolds exhibited a faster degradation rate for their much larger specific surface area. The culture of bone mesenchymal stem cell indicated that the composite nanofibrous poly(L ‐lactide) scaffold with 50 wt % nanohydroxyapatite showed the highest cells viability among various poly(L ‐lactide)‐based scaffolds. The strengthened biomimetic nanofibrous poly(L ‐lactide)/nanohydroxyapatite composite scaffold will be a potential candidate for bone tissue engineering. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Fabrication and characterization of chitosan/PVA with hydroxyapatite biocomposite nanoscaffolds

Nanofibrous biocomposite scaffolds of chitosan (CS), PVA, and hydroxyapatite (HA) were prepared by electrospinning. The scaffolds were characterized by FTIR, SEM, TEM, and XRD techniques. Tensile testing was used for the characterization of mechanical properties. Mouse fibroblasts (L929) attachment and proliferation on the nanofibrous scaffold were investigated by MTT assay and SEM observation. FTIR, TEM, and XRD results showed the presence of nanoHA in the scaffolds. The scaffolds have porous nanofibrous morphology with random fibers in the range of 100–700 nm diameters. The CS/PVA (90/10) fibrous matrix (without HA) showed a tensile strength of 3.1 ± 0.2 MPa and a tensile modulus 10 ± 1 MPa with a strain at failure of 21.1 ± 0.6%. Increase the content of HA up to 2% increased the ultimate tensile strength and tensile modulus, but further increase HA up to 5–10% caused the decrease of tensile strength and tensile modulus. The attachment and growth of mouse fibroblast was on the surface of nanofibrous structure, and cells' morphology characteristics and viability were unaffected. A combination of nanofibrous CS/PVA and HA that mimics the nanoscale features of the extra cellular matrix could be promising for application as scaffolds for tissue regeneration, especially in low or nonload bearing areas. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Fabrication of althea officinalis loaded electrospun nanofibrous scaffold for potential application of skin tissue engineering

The Althea Officinalis (AO) extract is well known as a traditional herbal drug for its wound healing ability owing to the anti-inflammatory and antimicrobial properties. Furthermore, its mucilaginous properties provide moisturizing and nutritional effects on skin cell proliferation. Therefore, AO extract can be applied in the temporary skin substitute for the ability to expedite the therapy duration. In this study, different concentrations of AO extract (0, 5, 10, 15, and 20 wt %) were incorporated into the nanofibrous scaffolds to study their potential for the skin tissue repairing. The desired scaffolds were prepared by electrospinning the blend of poly(ε -caprolactone) and gelatin as a synthesized and natural polymer. The electrospun nanofibers were characterized by SEM, FTIR, DSC, TGA, tensile, AO extract release, and cellular culture tests. This study proposed incorporating the AO extract into the nanofibrous scaffolds for accelerating the skin tissue repairing and the optimized amount of AO extract as about 15% was introduced for offering the most desirable electrospun scaffolds for this application. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48587.     

Characterization and cell response of electrospun Rana chensinensis skin collagen/poly(l‐lactide) scaffolds with different fiber orientations

Collagen was extracted from Rana chensinensis skin supplied from byproducts via an acid enzymatic extraction method. The R. chensinensis skin collagen (RCSC) and poly(l ‐lactide) (PLLA) were blended at a 3:7 ratio in 1,1,1,3,3,3‐hexafluoroisopropanol (HFIP) at a concentration of 10% (g/mL) and electrospun to produce nanofibers in an aligned and random orientation. For comparison, pure PLLA nanofibrous membranes with aligned and random nanofiber orientations were also produced. The secondary structure of the RCSC nanofibers was investigated by circular dichroism to confirm that the extracted substance was collagen. The presence of collagen in the blend nanofiber was verified by LSCM. The blended nanofibers showed uniform, smooth, and bead‐free morphologies and presented a smaller fiber diameter (278 and and 259 nm) than the pure the ones of PLLA (559 and and 439 nm) nanofibers. It was found that the addition of RCSC and the modification of the nanofiber's orientation affected the fiber's diameter and the crystallization of PLLA. The cell viability studies with human fibroblast cells demonstrated that the RCSC/PLLA nanofibrous membranes formed by electrospinning exhibited good biocompatibility and that the aligned scaffolds could regulate the cell morphology by inducing cell orientation. The empirical results in this study indicated that the aligned RCSC/PLLA nanofibrous membrane is a potential wound dressing candidate for skin regeneration. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45109.     

Microscale Diffusion Measurements and Simulation of a Scaffold with a Permeable Strut

Electrospun nanofibrous structures provide good performance to scaffolds in tissue engineering. We measured the local diffusion coefficients of 3-kDa FITC-dextran in line patterns of electrospun nanofibrous structures fabricated by the direct-write electrospinning (DWES) technique using the fluorescence recovery after photobleaching (FRAP) method. No significant differences were detected between DWES line patterns fabricated with polymer supplied at flow rates of 0.1 and 0.5 mL/h. The oxygen diffusion coefficients of samples were estimated to be ~92%–94% of the oxygen diffusion coefficient in water based on the measured diffusion coefficient of 3-kDa FITC-dextran. We also simulated cell growth and distribution within spatially patterned scaffolds with struts consisting of either oxygen-permeable or non-permeable material. The permeable strut scaffolds exhibited enhanced cell growth. Saturated depths at which cells could grow to confluence were 15% deeper for the permeable strut scaffolds than for the non-permeable strut scaffold.