The role of nanostructured mesoporous silicon in discriminating in vitro calcification for electrospun composite tissue engineering scaffolds

The impact of mesoporous silicon (PSi) particles-embedded either on the surface, or totally encapsulated within electrospun poly (ε-caprolactone) (PCL) fibers-on its properties as a tissue engineering scaffold is assessed. Our findings suggest that the resorbable porous silicon component can sensitively accelerate the necessary calcification process in such composites. Calcium phosphate deposition on the scaffolds was measured via in vitro calcification assays both at acellular and cellular levels. Extensive attachment of fibroblasts, human adult mesenchymal stem cells, and mouse stromal cells to the scaffold were observed. Complementary cell differentiation assays and ultrastructural measurements were also carried out; the levels of alkaline phosphatase expression, a specific biomarker for mesenchymal stem cell differentiation, show that the scaffolds have the ability to mediate such processes, and that the location of the Si plays a key role in levels of expression.     

Polymer blending or fiber blending: A comparative study using chitosan and poly(ε-caprolactone) electrospun fibers

Nonwoven membranes of poly(ε-caprolactone) (PCL) and chitosan (CS) were produced according to the two methods: by blending the polymers in solution followed by electrospinning – polymer blending method – and by simultaneous deposition of fibers electrospun from separate solutions – fiber blending (FB) method. The two production methods were compared by assessing fiber morphology, mass loss, swelling degree, water contact angle, and mechanical properties of the resulting electrospun membranes. Furthermore, the adhesion, proliferation, and morphology of human dermal fibroblasts on the eight types of scaffold produced were evaluated to assess if the blending method used would influence cell–scaffold interaction. Cell adhesion to the different scaffolds lied in the interval 40–60%, with the CS scaffold presenting the lowest value. Interestingly, cell proliferation was the same when comparing polymer blending and FB scaffolds having 3:1 or 1:3 PCL/CS ratios but very different when the ratio was 1:1 – the FB scaffold sustained a proliferation rate double that of the polymer blending scaffold. This work shows that, when blending polymers to improve the properties of a scaffold for tissue engineering or 3D cell culture, their spatial distribution may considerably affect scaffold's properties and should be considered as another parameter requiring optimization. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47191.     

Hyaluronic Acid and a Short Peptide Improve the Performance of a PCL Electrospun Fibrous Scaffold Designed for Bone Tissue Engineering Applications

Bone tissue engineering is a rapidly developing, minimally invasive technique for regenerating lost bone with the aid of biomaterial scaffolds that mimic the structure and function of the extracellular matrix (ECM). Recently, scaffolds made of electrospun fibers have aroused interest due to their similarity to the ECM, and high porosity. Hyaluronic acid (HA) is an abundant component of the ECM and an attractive material for use in regenerative medicine; however, its processability by electrospinning is poor, and it must be used in combination with another polymer. Here, we used electrospinning to fabricate a composite scaffold with a core/shell morphology composed of polycaprolactone (PCL) polymer and HA and incorporating a short self-assembling peptide. The peptide includes the arginine-glycine-aspartic acid (RGD) motif and supports cellular attachment based on molecular recognition. Electron microscopy imaging demonstrated that the fibrous network of the scaffold resembles the ECM structure. In vitro biocompatibility assays revealed that MC3T3-E1 preosteoblasts adhered well to the scaffold and proliferated, with significant osteogenic differentiation and calcium mineralization. Our work emphasizes the potential of this multi-component approach by which electrospinning, molecular self-assembly, and molecular recognition motifs are combined, to generate a leading candidate to serve as a scaffold for bone tissue engineering.     

Conducive 3D porous mesh of poly(ε-caprolactone) made via emulsion electrospinning

Use of Poly(ε-caprolactone) (PCL) as 3D porous scaffold, fibers and matrices has proved importance of this polymer in applications for tissue engineering besides others. Here we present an approach to generate uneven surfaced meshes of PCL via emulsion electrospinning with minimal use of organic solvent. Poly(vinyl alcohol) (PVA) was used as template polymer providing stability and alignment to PCL phase during electrospinning of oil-in-water emulsion of PCL. The emulsion properties including particle size, inter-particle distance and viscosity depended on the concentrations of PCL and PVA. Higher PVA content led to formation of smaller oil phase particles resulting into higher viscosity of the emulsion while a higher PCL content led to the formation of larger oil phase particles and correspondingly lower viscosity of the emulsion. A correlation between particle size of emulsion and diameter of the fibers obtained after electrospinning was found. The composite meshes of PCL-PVA obtained via emulsion electrospinning were washed with water to generate uneven surface on the meshes which was found to be highly favorable for cell growth in comparison to a uniform mesh of PCL made via solution electrospinning.     

Fabrication and characterization of hydrophilic poly(ε‐caprolactone)/pluronic P123 electrospun fibers

Poly(ε‐caprolactone) (PCL) has been widely investigated for tissue engineering applications because of its good biocompatibility, biodegradability, and mechanical properties; however hydrophobic nature of PCL has been a colossal obstacle toward achieving scaffolds which offer satisfactory cell attachment and proliferation. To produce highly hydrophilic electrospun fibers, PCL was blended with pluronic P123 (P123) and the resulted electrospun scaffolds physiochemical characteristics such as fiber morphology, thermal behavior, crystalline structure, mechanical properties, and wettability were investigated. Moreover molecular dynamic (MD) simulation was assigned to evaluate the blended and neat PCL/water interactions. Presence of P123 at the surface of electrospun blended fibers was detected using ATR‐FTIR analysis. P123 effectiveness in improving the hydrophilicity of the scaffolds was demonstrated by water contact angel which experienced a sharp decrease from 132° corresponding to the neat PCL to almost 0° for all blended samples. Also a steady increase in water uptake ratio was observed for blended fibers as P123 content increased. The 90/10 blend ratio had the maximum tensile strength, elongation at break and crystallinity percentage. Therefore 90/10 blend ratio of PCL/P123 can balance the mechanical properties and bulk hydrophilicity of the resulted electrospun scaffold and would be a promising candidate for tissue engineering application. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43345.     

Electrospun poly(L‐lactide)/poly(ε‐caprolactone) blend fibers and their cellular response to adipose‐derived stem cells

Polymer blending is one of the most effective methods for providing new, desirable biocomposites for tissue‐engineering applications. In this study, electrospun poly(L ‐lactide)/poly(ε‐caprolactone) (PLLA/PCL) blend fibrous membranes with defect‐free morphology and uniform diameter were optimally prepared by a 1 : 1 ratio of PLLA/PCL blend under a solution concentration of 10 wt %, an applied voltage of 20 kV, and a tip‐to‐collector distance of 15 cm. The fibrous membranes also showed a porous structure and high ductility. Because of the rapid solidification of polymer solution during electrospinning, the crystallinity of electrospun PLLA/PCL blend fibers was much lower than that of the PLLA/PCL blend cast film. To obtain an initial understanding of biocompatibility, adipose‐derived stem cells (ADSCs) were used as seed cells to assess the cellular response, including morphology, proliferation, viability, attachment, and multilineage differentiation on the PLLA/PCL blend fibrous scaffold. Because of the good biocompatibility and nontoxic effect on ADSCs, the PLLA/PCL blend electrospun fibrous membrane provided a high‐performance scaffold for feasible application in tissue engineering using ADSCs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Carbon nanotubes and silver nanoparticles for multifunctional conductive biopolymer composites

This article fabricates and characterizes the combination of single walled carbon nanotubes (SWCNTs) and silver nanoparticles (Ag) with a biodegradable polymer matrix. Different SWCNT amount were mixed with Ag nanoparticles and introduced in the poly(ε-caprolactone) (PCL) polymer matrix by solvent cast process. Nanostructure synergistic effects were evaluated in terms of morphological, electrical, dielectrical, mechanical and biological properties of binary PCL/Ag, PCL/SWCNTs and ternary PCL/Ag/SWCNTs composites. Results showed a good dispersion of nanostructures in the PCL and an increase of Young modulus with silver content in the binary systems. The PCL/Ag composites exhibited poor electrical properties, while in PCL/Ag/SWCNTs ternary films higher values of conductivity were measured compared to both binary composites. Results obtained in this research indicate that Ag particles facilitate the formation of conductive pathways in the presence of SWCNTs, they act as conductive bridges among nanotube bundles and facilitate the electron transfer. The addition of a small percentage of SWCNTs promoted significantly the electrical properties of PCL/Ag nanohybrid films. Biocompatibility of binary and ternary composites, evaluated by human mesenchymal stem cells-bone marrow derived (hBM-MSCs), suggests that the combination of Ag nanoparticles and SWCNTs with a biodegradable polymer opens new perspectives for biomedical applications.     

Electrospun PCL and PLA hybrid nanofibrous scaffolds containing Nigella sativa herbal extract for effective wound healing

Black seed (Nigella sativa [NS]) is used in traditional medicine as an antibacterial agent. In this study, novel hybrid scaffolds were manufactured from poly(ɛ-caprolactone[PCL])/ Poly(lactic acid [PLA]) with NS extract by double-nozzle electrospinning for wound healing application. Optimal conditions were found using response surface methodology including feed rate 0.8 ml/hr, voltage 20 kV and PLA 8% /PCL 10% concentrations. The effect of NS extract on the properties of the scaffold was evaluated by scanning electron microscopy, contact angle, and mechanical test. The PLA-PCL/NS 20% beadles, and smooth nanofibrous web was obtained as the optimum scaffold with an average diameter of 638 ± 69 nm and the contact angle of 44°. In addition, the biological properties of the scaffolds such as antibacterial against Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative) bacteria, MTT assay, extract release, and cell growth (human mesenchymal stem cells) were examined. Incorporation of NS extract into the nanofibers caused to enhance the biological properties, cell viability and cell proliferation without toxicity.     

Evaluation of the chondrogenic differentiation of mesenchymal stem cells on hybrid biomimetic scaffolds

Hybrid materials are widely and promisingly used as scaffolds in cartilage tissue remodeling. In this study, hybrid scaffolds consist of polycaprolactone (PCL), poly(vinyl alcohol) (PVA) with/without gelatin (GEL) to mimic natural cartilage extracellular matrix (ECM) were investigated. Scaffolds were prepared by freeze drying and characterized by scanning electron microscopy and compressive mechanical testing. Biological assays of mesenchymal stem cell (MSC) cultures, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide, and dimethyl methylene blue were performed, and real‐time polymerization chain reaction analysis of the cartilage‐specific ECM gene marker expression was done. The results show an open interconnected porous structure with a compression modulus of 1.27 ± 0.04 MPa. The surface of the scaffolds showed an excellent efficiency in the adhesion and proliferation of MSCs. A significant increase in the proteoglycan content from 3.70 ± 0.96 to 5.4 ± 1.13 μg/mL was observed after 14 days in the PCL–PVA–GEL scaffolds. The expression amount of the sex‐determining region Y–Box 9 (SOX9) and collagen II (COL2) mRNA levels of the MSCs showed significant increases in SOX9 and COL2, respectively in comparison with PCL–PVA scaffold. The study revealed that the aforementioned scaffold as a blend of natural and synthetic polymers may be a promising substrate in tissue engineering for cartilage repair with MSC transplantation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40635.     

β-TCP scaffold coated with PCL as biodegradable materials for dental applications

Requirements for an ideal scaffold include biocompatibility, biodegradability, mechanical strength and sufficient porosity and pore dimensions. Beta tricalcium phosphate (β-TCP) has competent biocompatibility and biodegradability, but has low mechanical strength because of its porous structure. Polycaprolactone (PCL) is a biodegradable polymer with elastic characteristics and good biocompatibility. In this study, β-TCP/PCL composites were prepared in different ratio and their morphology, phase content, mechanical properties, biodegradation and biocompatibility were investigated. After coating, surfaces of β-TCP scaffolds were covered with the PCL while some of the pores were partially clogged. The compression and bending strength of β-TCP scaffolds were significantly enhanced by PCL coating. The degradation rate of the scaffold in Tris buffer was reduced with higher content of the PCL coating. MTT and ALP assays showed that the osteoblast cells could proliferate and differentiate on PCL coated scaffolds as well as on bare β-TCP scaffolds. Based on the comprehensive analysis achieved in this study, it is concluded that the β-TCP/PCL composite scaffold fabricated with 40% β-TCP and 5% PCL exhibits optimum properties suitable for dental applications.     

The odontogenic differentiation of human dental pulp stem cells on hydroxyapatite-coated biodegradable nanofibrous scaffolds

The authors aimed to design nanofibrous (NF) scaffolds that facilitate odontogenic and osteogenic differentiation of human dental pulp-derived mesenchymal stem cells (DPSCs) in vitro. For this purpose, hydroxyapatite (HA)–loaded poly (L-lactic acid)/poly (?-caprolactone) (PLLA:PCL 2;1) blend NFs were prepared using the electrospinning method. Alizarin red activity and cell viability were evaluated by MTT assay, and SEM revealed the proliferation properties of NF scaffolds. QRT-PCR results demonstrated that HA-loaded PLLA/PCL can lead to osteoblast/odontoblast differentiation in DPSCs through the up-regulation of related genes, thus indicating that electrospun biodegradable PCL/PLA/HA has remarkable prospects as scaffolds for bone and tooth tissue engineering.     

Preparation and characterization of poly(ɛ-caprolactone) nonwoven mats via melt electrospinning

Laser melt electrospinning is a novel technology to produce nonwoven scaffolds for tissue engineering (TE) applications. This solvent-free process is far safer than common solution electrospinning. In this paper, we demonstrated the poly(?-caprolactone) (PCL) fibers diameters could be governed from 3 to 12 μm with changing electrospinning parameters. The various diameters can meet the needs of scaffold properties such as porosity, pore size, etc. Our experiential results also showed that the fibers diameter tended to decrease as laser current increased. The degradation of PCL molecular chains often occurs in the melt electrospinning process due to mechanical scission and thermal degradation. The crystallinity of as-spun PCL fibers was approximately equal to that of the annealing fibers by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). In our experiential, the collected PCL electrospun fibers often fused together to form a three-dimension network structure, which is favorable to mechanical properties.     

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.     

Morphology,wettability, and mechanical properties of polycaprolactone/hydroxyapatite composite scaffolds with interconnected pore structures fabricated by a mini‐deposition system

A new mini‐deposition system (MDS) was developed to fabricate scaffolds with interconnected pore structures and anatomical geometry for bone tissue engineering. Polycaprolactone/hydroxyapatite (PCL/HA) composites with varying hydroxyapatite (HA) content were adopted to manufacture scaffolds by using MDS with a porosity of 54.6%, a pore size of 716 μm in the x‐y plane, and 116 μm in the z direction. The water uptake ratio and compressive modulus of PCL/HA composite scaffold increase from 8 to 39% and from 26.5 to 49.8 MPa, respectively, as the HA content increases from 0 to 40%. PCL/HA composite scaffolds have better wettability and mechanical properties than pure PCL scaffold. A PCL/HA composite scaffold for mandible bone repair was successfully fabricated with both interconnected pore structures and anatomical shape to demonstrate the versatility of MDS. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Development of a novel glucosamine/silk fibroin–chitosan blend porous scaffold for cartilage tissue engineering applications

Silk fibroin–chitosan blend is reported to be an attractive scaffold material for tissue engineering applications. In our earlier study, we developed a scaffold having an optimal silk fibroin–chitosan blend ratio of 80:20 and proved its potentiality for cartilage tissue engineering applications. Glucosamine is one of the major structural components of cartilage tissue. The present work investigates the effect of glucosamine components on the physicochemical and biocompatibility properties of this scaffold. To this end, varied amounts of glucosamine were added to silk fibroin–chitosan blend with the aim of improving various scaffold properties. The addition of glucosamine components did not show any significant change in physicochemical properties of silk fibroin–chitosan blend scaffolds. The composite scaffold showed an open pore structure with desired pore size and porosity. However, cell culture study using human mesenchymal stem cells derived from umbilical cord blood revealed an overall increase in cell supportive properties of glucosamine-added scaffolds. Cell viability, cell proliferation and glycosaminoglycan assays confirmed enhanced cell viability and proliferation of mesenchymal stem cells. Thus, this study demonstrated the beneficial effect of glucosamine on improving the cell supportive property of silk fibroin–chitosan blend scaffolds making it more potential for cartilage tissue regeneration. To the best of our knowledge, this is the first report on the study of glucosamine-added silk fibroin–chitosan blend porous scaffolds seeded with mesenchymal stem cells derived from umbilical cord blood.     

Integrated three‐dimensional fiber/hydrogel biphasic scaffolds for periodontal bone tissue engineering

Combining a tissue engineering scaffold made of a load‐bearing polymer with a hydrogel represents a powerful approach to enhancing the functionalities of the resulting biphasic construct, such as its mechanical properties or ability to support cellular colonization. This research activity was aimed at the development of biphasic scaffolds through the combination of an additively manufactured poly(?‐caprolactone) (PCL) fiber construct and a chitosan/poly(γ‐glutamic acid) polyelectrolyte complex hydrogel. By investigating a set of layered structures made of PCL or PCL/hydroxyapatite composite, biphasic scaffold prototypes with good integration of the two phases at the macroscale and microscale were developed. The biphasic constructs were able to absorb cell culture medium up to 10‐fold of their weight, and the combination of the two phases had a significant influence on compressive mechanical properties compared with hydrogel or PCL scaffold alone. In addition, due to the presence of chitosan in the hydrogel phase, biphasic scaffolds exerted a broad‐spectrum antibacterial activity. The developed biphasic systems appear well suited for application in periodontal bone regenerative approaches in which a biodegradable porous structure providing mechanical stability and a hydrogel phase functioning as absorbing depot of endogenous proteins are simultaneously required. © 2016 Society of Chemical Industry     

Minocycline Loaded Hybrid Composites Nanoparticles for Mesenchymal Stem Cells Differentiation into Osteogenesis

Bone transplants are used to treat fractures and increase new tissue development in bone tissue engineering. Grafting of massive implantations showing slow curing rate and results in cell death for poor vascularization. The potentials of biocomposite scaffolds to mimic extracellular matrix (ECM) and including new biomaterials could produce a better substitute for new bone tissue formation. A purpose of this study is to analyze polycaprolactone/silk fibroin/hyaluronic acid/minocycline hydrochloride (PCL/SF/HA/MH) nanoparticles initiate human mesenchymal stem cells (MSCs) proliferation and differentiation into osteogenesis. Electrospraying technique was used to develop PCL, PCL/SF, PCL/SF/HA and PCL/SF/HA/MH hybrid biocomposite nanoparticles and characterization was analyzed by field emission scanning electron microscope (FESEM), contact angle and Fourier transform infrared spectroscopy (FT-IR). The obtained results proved that the particle diameter and water contact angle obtained around 0.54 ± 0.12 to 3.2 ± 0.18 µm and 43.93 ± 10.8° to 133.1 ± 12.4° respectively. The cell proliferation and cell-nanoparticle interactions analyzed using (3-(4,5-dimethyl thiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt) MTS assay (Promega, Madison, WI, USA), FESEM for cell morphology and 5-Chloromethylfluorescein diacetate (CMFDA) dye for imaging live cells. Osteogenic differentiation was proved by expression of osteocalcin, alkaline phosphatase activity (ALP) and mineralization was confirmed by using alizarin red (ARS). The quantity of cells was considerably increased in PCL/SF/HA/MH nanoparticles when compare to all other biocomposite nanoparticles and the cell interaction was observed more on PCL/SF/HA/MH nanoparticles. The electrosprayed PCL/SF/HA/MH biocomposite nanoparticle significantly initiated increased cell proliferation, osteogenic differentiation and mineralization, which provide huge potential for bone tissue engineering.     

Biodegradable Poly-ε-Caprolactone Scaffolds with ECFCs and iMSCs for Tissue-Engineered Heart Valves

Clinically used heart valve prostheses, despite their progress, are still associated with limitations. Biodegradable poly-ε-caprolactone (PCL) nanofiber scaffolds, as a matrix, were seeded with human endothelial colony-forming cells (ECFCs) and human induced-pluripotent stem cells-derived MSCs (iMSCs) for the generation of tissue-engineered heart valves. Cell adhesion, proliferation, and distribution, as well as the effects of coating PCL nanofibers, were analyzed by fluorescence microscopy and SEM. Mechanical properties of seeded PCL scaffolds were investigated under uniaxial loading. iPSCs were used to differentiate into iMSCs via mesoderm. The obtained iMSCs exhibited a comparable phenotype and surface marker expression to adult human MSCs and were capable of multilineage differentiation. EFCFs and MSCs showed good adhesion and distribution on PCL fibers, forming a closed cell cover. Coating of the fibers resulted in an increased cell number only at an early time point; from day 7 of colonization, there was no difference between cell numbers on coated and uncoated PCL fibers. The mechanical properties of PCL scaffolds under uniaxial loading were compared with native porcine pulmonary valve leaflets. The Young’s modulus and mean elongation at F_max of unseeded PCL scaffolds were comparable to those of native leaflets (p = ns.). Colonization of PCL scaffolds with human ECFCs or iMSCs did not alter these properties (p = ns.). However, the native heart valves exhibited a maximum tensile stress at a force of 1.2 ± 0.5 N, whereas it was lower in the unseeded PCL scaffolds (0.6 ± 0.0 N, p < 0.05). A closed cell layer on PCL tissues did not change the values of F_max (ECFCs: 0.6 ± 0.1 N; iMSCs: 0.7 ± 0.1 N). Here, a successful two-phase protocol, based on the timed use of differentiation factors for efficient differentiation of human iPSCs into iMSCs, was developed. Furthermore, we demonstrated the successful colonization of a biodegradable PCL nanofiber matrix with human ECFCs and iMSCs suitable for the generation of tissue-engineered heart valves. A closed cell cover was already evident after 14 days for ECFCs and 21 days for MSCs. The PCL tissue did not show major mechanical differences compared to native heart valves, which was not altered by short-term surface colonization with human cells in the absence of an extracellular matrix.     

Fabrication and characterization of multiwalled carbon nanotube–loaded interconnected porous nanocomposite scaffolds

Novel nanocomposite porous scaffolds based on poly(?-caprolactone) (PCL) and multiwalled carbon nanotubes (MWCNTs) were manufactured by a compression-molding/polymer-leaching approach utilizing cryomilling for homogeneous dispersion of nanotubes and blending of polymers. Addition of MWCNTs to PCL and PCL/polyglycolide (PGA) blends resulted in significant changes to scaffold morphology compared to control samples despite persistent interconnected porosity. Several structures exhibiting rough and nanotextured surfaces were observed. Mean pore sizes were in the range of ～3–5?µm. The nanocomposites presented good mechanical and water uptake properties. The results of this research provide significant insight into a strategy for producing nanocomposite scaffolds with interconnected porosity.     

Influence of polycaprolactone/polyglycolide blended electrospun fibers on the morphology and mechanical properties of polycaprolactone

Polycaprolactone (PCL) and polyglycolide (PGA) are two biopolymers that have been used as in situ biomedical devices for various applications. The obstacle of creating a composite that captures the benefit of PCL's long degradation time, while acquiring the strength from PGA is overcoming the lack of surface adhesion between the two biopolymers for stress transfer to occur. This study investigates the use of miscible PCL‐PGA blended fibers, created by electrospinning, to increase the interfacial bonding of fibers to the PCL matrix of the polymer–polymer composite. The use of the blended fibers will thereby create the ability of load transfer from the long‐term PCL matrix to the stronger PCL‐PGA fiber reinforcement. The incorporation of the PCL‐PGA fibers was able to increase the tensile yield strength and Young's modulus over that of the bulk PCL, while decreasing the percent elongation at break. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40224.