Composite Nanofiber Scaffolds Research Articles

Dexamethasone loaded multi-layer poly-l-lactic acid/pluronic P123 composite electrospun nanofiber scaffolds for bone tissue engineering and drug delivery

In tissue engineering, it is common to mix drugs that can control proliferation and differentiation of cells into polymeric solutions as part of composite to get bioactive scaffolds. However, direct incorporation of drugs might potentially result in undesired burst release. To overcome this problem, here we developed electrospun multilayer drug loaded poly-l-lactic acid/pluronic P123 (PLLA–P123) composite scaffolds. The drug was loaded into the middle layer. The surface, the mechanical and physiochemical properties of the scaffolds were evaluated. The drug release profiles were monitored. Finally, the osteogenic proliferation and differentiation potential were determined. The scaffolds fabricated here have appropriate surface properties, but with different mechanical strength and osteogenic proliferation and differentiation. Multi-layer scaffolds where the drug was in the middle layer and PLLA-plasma and PLLA–P123 with cover layer showed the best osteogenic proliferation and differentiation than the other groups of scaffolds. The drug release profiles of the scaffolds were completely different: single layer scaffolds showed burst release within the first day, while multilayer scaffolds showed controlled release. Therefore, the multilayer drug loaded scaffolds prepared have dual benefits can provide both better osteogenesis and controlled release of drugs and bioactive molecules at the implant site.

Rational design of bone extracellular matrix mimicking tri-layered composite nanofibers for bone tissue regeneration

Multilayer nanofibrous scaffolds are gaining great attention in biomedical fields especially as tissue regeneration materials as well as drug delivery devices. Herein, we report the unique design of a tri-layered composite nanofiber scaffold mimicking the bone ECM for bone tissue regeneration. The tri-layered membrane consists of a superficial layer of PVA-PVAc loaded with simvastatin to initiate and improve osteogenesis process via sustained release of the drug as well as the excellent bioactivity of its blended polymers. The PCL-CA-β-tcp middle layer acts as a platform for stimulating the bio mineralization process mimicking the apatite like layer which mainly start after the first week of implantation. The final PCL layer performs as the fundamental layer to keep mechanical properties of the composite mat. The as prepared scaffolds were investigated in terms of morphology characterization, physiochemical properties, biomimetic mineralization, drug release and biocompatibility. The in vitro drug release study confirms the sustained release of simvastatin from the tri-layered membrane by obeying the Korsemeyer-Peppas, Higushi model and Kopcha model. The results demonstrate that the proposed biocompatible tri-layered scaffold will be a promising future material for bone tissue regeneration application by providing higher mineralization, enhanced cell attachment and proliferation.

Antibacterial, sustained drug release and biocompatibility studies of electrospun poly(ε-caprolactone)/chloramphenicol blend nanofiber scaffolds

Controlled drug release and antibacterial properties of electrospun nanofiber depend on slow release of drug molecules to the targeted area by diffusion and antibacterial properties of drug embedded in the nanofiber. In the present study, chloramphenicol (CAP), an antibacterial drug has been incorporated in poly(ε-caprolactone) (PCL) nanofibers in the weight content of 5–20 wt% by electrospinning. It was found that the fiber diameter and hydrophilic nature of nanofibers increased with increase in CAP content. The latter phenomenon is expected to facilitate biocompatibility of scaffolds. The scaffolds showed excellent antibacterial properties against gram positive (Staphylococcus aureus and Bacillus subtilis) as well as gram negative (Escherichia coli, Pseudomonas aeruginosa and Flavobacterium devorans) bacterial strains commonly associated with wound and burn infections. In-vitro drug release studies were carried out in phosphate buffer saline at pH ∼ 7.4. The release was found to be saturated in about 20 days and the maximum release was ∼80%. Nanofiber scaffolds with 5 wt% CAP content showed the highest release rate among the scaffolds studied, which could be attributed to the smaller fiber diameter of this scaffold leading to higher surface area. The composite nanofiber scaffolds were further studied for cell adhesion, proliferation and toxicity using human colon colorectal epithelial cells (HCT 116 WT) in vitro. The cells are found to show excellent adhesion and proliferation on both PCL and CAP embedded scaffolds in large numbers. However, CAP loaded scaffolds showed better cell proliferation than that of neat PCL counterpart.

Biomineralized poly (l-lactic-co-glycolic acid)-tussah silk fibroin nanofiber fabric with hierarchical architecture as a scaffold for bone tissue engineering

In bone tissue engineering, the fabrication of a scaffold with a hierarchical architecture, excellent mechanical properties, and good biocompatibility remains a challenge. Here, a solution of polylactic acid (PLA) and Tussah silk fibroin (TSF) was electrospun into nanofiber yarns and woven into multilayer fabrics. Then, composite scaffolds were obtained by mineralization in simulated body fluid (SBF) using the multilayer fabrics as a template. The structure and related properties of the composite scaffolds were characterized using different techniques. PLA/TSF (mass ratio, 9:1) nanofiber yarns with uniform diameters of 72±9μm were obtained by conjugated electrospinning; the presence of 10wt% TSF accelerated the nucleation and growth of hydroxyapatite on the surface of the composite scaffolds in SBF. Furthermore, the compressive mechanical properties of the PLA/TSF multilayer nanofiber fabrics were improved after mineralization; the compressive modulus and stress of the mineralized composite scaffolds were 32.8 and 3.0 times higher than that of the composite scaffolds without mineralization, respectively. Interestingly, these values were higher than those of scaffolds containing random nanofibers. Biological assay results showed that the mineralization and multilayer fabric structure of the composite nanofiber scaffolds significantly increased cell adhesion and proliferation and enhanced the mesenchymal stem cell differentiation toward osteoblasts. Our results indicated that the mineralized nanofiber scaffolds with multilayer fabrics possessed excellent cytocompatibility and good osteogenic activity, making them versatile biocompatible scaffolds for bone tissue engineering.

Effect of multi wall carbon nanotubes on characteristics and morphology of nanofiber scaffolds composited of MWNTs/silk fibroin

Composite of multi wall carbon nanotubes (MWNTs) and silk fibroin were electrospun to nanofiber scaffolds with average diameter ranged from 46.2 to 100nm. The effect of increasing the percentage of the MWNTs was evaluated on properties, characterizes and morphology of composite nanofiber scaffolds. Solution concentration, electric field, distance of needle from collector and flow rate were optimized for electrospinning. Optical and scanning electron microscope were used to study the morphology and diameter of composite nanofibers. The properties and characterizes were considered by using the FTIR spectroscopy, X-ray and Raman spectroscopy in addition, the electrical conductivity was measured utilizing Four-Point Probe method. Results showed that augmentation of the MWNTs had a small effect on the nanofiber surface. A growth was seen in the composite nanofiber diameter by increasing the MWNTs. Chemical interaction was not happened between MWNTs and silk fibroin based on FTIR spectroscopy and X-ray analysis also, crystallization of composite nanofibers grew by adding MWNTs. Raman spectroscopy proved that MWNTs were incorporated in the silk fibers. The electrical conductivity of composite nanofiber scaffolds was increased by increment of the MWNTs.

Polydopamine-Templated Hydroxyapatite Reinforced Polycaprolactone Composite Nanofibers with Enhanced Cytocompatibility and Osteogenesis for Bone Tissue Engineering.

Nanohydroxyapatite (HA) synthesized by biomimetic strategy is a promising nanomaterial as bone substitute due to its physicochemical features similar to those of natural nanocrystal in bone tissue. Inspired by mussel adhesive chemistry, a novel nano-HA was synthesized in our work by employing polydopamine (pDA) as template under weak alkaline condition. Subsequently, the as-prepared pDA-templated HA (tHA) was introduced into polycaprolactone (PCL) matrix via coelectrospinning, and a bioactive tHA/PCL composite nanofiber scaffold was developed targeted at bone regeneration application. Our research showed that tHA reinforced PCL composite nanofibers exhibited favorable cytocompatibility at given concentration of tHA (0-10 w.t%). Compared to pure PCL and traditional nano-HA enriched PCL (HA/PCL) composite nanofibers, enhanced cell adhesion, spreading and proliferation of human mesenchymal stem cells (hMSCs) were observed on tHA/PCL composite nanofibers on account of the contribution of pDA present in tHA. More importantly, tHA nanoparticles exposed on the surface of composite nanofibers could further promote osteogenesis of hMSCs in vitro even in the absence of osteogenesis soluble inducing factors when compared to traditional HA/PCL scaffolds, which was supported by in vivo test as well according to the histological analysis. Overall, our study demonstrated that the developed tHA/PCL composite nanofibers with enhanced cytocompatibility and osteogenic capacity hold great potential as scaffolds for bone tissue engineering.

Field-actuated antineoplastic potential of smart and versatile PEO–bPEI electrospun scaffold by multi-staged targeted co-delivery of magnetite nanoparticles and niclosamide–bPEI complexes

A PEO–bPEI based composite nanofiber scaffold has been realized for field actuated targeted delivery of magnetite nanoparticles and bPEI–niclosamide complexes for efficient management of cancer prognosis.

Tyrosinase-Mediated Construction of a Silk Fibroin/Elastin Nanofiber Bioscaffold.

Elastin has characteristics of elasticity, biological activity, and mechanical stability. In the present work, tyrosinase-mediated construction of a bioscaffold with silk fibroin and elastin was carried out, aiming at developing a novel medical biomaterial. The efficiency of enzymatic oxidation of silk fibroin and the covalent reaction between fibroin and elastin were examined by spectrophotometry, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and size exclusion chromatography (SEC). The properties of composite air-dried and nanofiber scaffolds were investigated. The results reveal that elastin was successfully bonded to silk fibroins, resulting in an increase in molecular weight of fibroin proteins. ATR-FTIR spectra indicated that tyrosinase treatment impacted the conformational structure of fibroin-based membrane. The thermal behaviors and mechanical properties of the tyrosinase-treated scaffolds were also improved compared with the untreated group. NIH/3T3 cells exhibited optimum densities when grown on the nanofiber scaffold, implying that the nanofiber scaffold has enhanced biocompatibility compared to the air-dried scaffold. A biological nanofiber scaffold constructed from tyrosinase-treated fibroin and elastin could potentially be utilized in biomedical applications.

Anti-Neoplastic Cytotoxicity of SN-38-Loaded PCL/Gelatin Electrospun Composite Nanofiber Scaffolds against Human Glioblastoma Cells In Vitro

Electrospun poly(ε-caprolactone) (PCL)/gelatin (GT) scaffolds were developed to provide controlled release of 7-ethyl-10-hydroxy camptothecin (SN-38). Acetic acid was introduced to improve the miscibility of PCL and GT to produce a homogeneous nanofiber membrane mixture. The effect of SN-38 content in binary mixtures on processability, fiber morphology, water sorption, swelling, and drug release was investigated. Electrospun PCL/GT blend nonwoven fibers showed fiber surface roughness, decreased PCL crystallinity, and increased swelling with increasing drug content of 1, 2, and 4 wt %. Additionally, increasing the SN-38 concentration reduced the degradation rate of the GT. Furthermore, we hypothesize the existence of a drug content saturation point in the monoaxial fiber to explain the different drug release patterns of PG2 compared with those of PG1 and PG4. The matrix also showed good biodegradation and anti-tumor function. Our results demonstrate that SN-38-loaded PCL/GT fibers can be obtained by electrospinning. The SN-38-loaded fibers merit further evaluation as a means to potentially prevent locoregional recurrence following surgical tumor resection.

Electrospun composites of PHBV/pearl powder for bone repairing

Electrospun fiber has highly structural similarity with natural bone extracelluar matrix (ECM). Many researches about fabricating organic–inorganic composite materials have been carried out in order to mimic the natural composition of bone and enhance the biocompatibility of materials. In this work, pearl powder was added to the poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and the composite nanofiber scaffold was prepared by electrospinning. Mineralization ability of the composite scaffolds can be evaluated by analyzing hydroxyapatite (HA) formation on the surface of nanofiber scaffolds. The obtained composite nanofiber scaffolds showed an enhanced mineralization capacity due to incorporation of pearl powder. The HA formed amount of the composite scaffolds was raised as the increase of pearl powder in composite scaffolds. Therefore, the prepared PHBV/pearl composite nanofiber scaffolds would be a promising candidate as an osteoconductive composite material for bone repairing.

Silver‐nanoparticle‐Incorporated composite nanofibers for potential wound‐dressing applications

ABSTRACTThe aim of this study was to develop stable and porous poly(ethylene oxide) (PEO)–polycaprolactone blended and silver nanoparticle (Ag NP) incorporated composite nanofiber scaffolds as antibacterial wound dressings. A facile approach for the in situ synthesis of Ag NPs was explored. In this synthesis method, N,N‐dimethylformamide (DMF) was used as a solvent; it also acted as reducing agent for Ag NP formation. The stabilization of Ag NPs in the fibers was accomplished by PEO, which in turn acted as a reducing agent along with DMF. The successful synthesis of crystalline Ag NPs was confirmed by various characterization techniques. Thermogravimetric analysis, wettability, and surface roughness analysis of the nanofibers were done to examine the suitability of the scaffold for wound dressing. The as‐synthesized composite nanofibers possessed good roughness, wettability, and antibacterial potential against recombinant green fluorescent proteins expressing antibiotic‐resistant Escherichia coli. Thus, the nanofiber scaffold fabricated by this approach could serve as an ideal wound dressing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42473.

4-Vinylbenzene Boronic Acid–Hydroxy Apatite/Polyvinyl Alcohol Based Nanofiber Scaffold Synthesized by UV-Activated Reactive Electrospinning

In this study, we prepared photo-crosslinked modified HAP (hydroxy apatite)/polyvinyl alcohol (PVA) composite nanofiber scaffold for cell growth applications. HAP was synthesized and then modified with 4-vinylbenzene boronic acid (VBBA) to obtain 4-VBBA-HAP. By means of the simultaneous UV electrospinning technique 4-VBBA-HAP/PVA composite was obtained. The structure and morphology of electrospun membranes were investigated by scanning electron microscopy) and Fourier transform infrared spectroscopy technique. Nanofibers were treated with collagen solution via the spraying method. For the cell culture applications ECV304 and SAOS cells were seeded on the chosen electrospun fibrous scaffolds.

Preparation and properties of nanodiamond/poly(lactic acid) composite nanofiber scaffolds

Nanodiamonds (NDs) were employed for the first time to enhance the mechanical properties of poly(lactic acid) (PLA)-based nanofiber scaffolds. Uniform ND/PLA composite nanofibers can be electrospun at <1 wt% loading of NDs. The introduction of NDs improved the thermal stability of PLA-based nanofibers. Fourier transform infrared spectroscopy results demonstrated good adhesion between ND nanofillers and PLA matrix. Following the addition of NDs, the four mechanical indicators, tensile strength, Young’s modulus, elongation at break and fracture toughness of ND/PLA composite nanofiber membranes increased accompanied by the later decrease with the rise of ND content. The four indicators achieved their respective maximum value at 1 wt% ND content, which revealed 2.4 fold increase of tensile strength, 1.6 fold augment of Young’s modulus, 1.4 fold elevation of elongation at break, and 4.8 fold growth of fracture toughness, respectively. Compared with the tensile strength and Young’s modulus of neat PLA, ND nanofillers exhibited the best reinforcing ability for PLA-based composite nanofibers, which was attributed to the effective interfacial adhesion between PLA and rigid ND particles and the good dispersion of NDs in PLA matrix. The ND/PLA composite nanofiber membranes with improved mechanical properties possess potential application in biomedical engineering.

Airbrushed composite polymer Zr-ACP nanofiber scaffolds with improved cell penetration for bone tissue regeneration.

Electrospun polymer nanofibers have multiple applications in the tissue engineering field despite limited cell penetration within the scaffolds and slow synthesis rates. Airbrushing, a proposed alternative to traditional electrospinning, is a technique capable of synthesizing open structure nanofiber scaffolds at high rates. In this study, three biocompatible polymers-poly-D,L-lactic acid (P-DL-LA), polycaprolactone (PCL), and poly(methyl methacrylate) (PMMA), were airbrushed to form networks for bone tissue regeneration. All three polymers were loaded with up to 20% (w/w) zirconium-modified amorphous calcium phosphate (Zr-ACP). A simple one-step mix and straightforward material deposition yielded open structure networks with well-distributed Zr-ACP. Cell penetration within the airbrushed scaffolds was found to be more than twice the cell penetration within conventional electrospun networks. The airbrushed polymer network supported cell growth and differentiation. Cells grown on the Zr-ACP in P-DL-LA fibers exhibited improved levels of osteocalcin protein with an increase in the Zr-ACP content by day 16. This airbrushing method promises to be a viable and attractive alternative to currently used electrospinning techniques in the formation of composite 3D nanofiber scaffolds for tissue engineering applications.

Fabrication and Characterization of Poly(L-lactic acid)-polycaprolactone Composite Nanofiber Scaffolds†

The feasibility of fabrication of poly(L-lactic acid)-polycaprolactone(PLLA-PCL) composite nanofiber scaffolds using the gel extraction phase separation in the dioxane /ethanol solvent system was verified and the effects of gelation temperature,the ratio of PLLA and PCL,polymer concentration,the ratio of dioxane and ethanal and porogen on the structure and performance of PLLA-PCL composite nanofiber scaffolds were investigated. The results show that PLLA-PCL composite nanofiber scaffolds with 50—500 nm nanofiber structure similar to the extracellular matrixc(ECM) can be fabricated when the gelation temperature is in the range of- 20—- 10 ℃,PCL content of 30% to 50%,the content of non-solvent no more than 15%,the porogen proportion no more than 1∶ 1. The additional PCL play a role of toughening,and the elastic modulus of the composite fiber scaffolds decrease with the increasing of PCL mass fraction. When the content of PCL is 30%,the compatibility and crystallinity of the composite fiber scaffolds are the best,and the composite fiber scaffolds have a good bioactivity and certain biodegradability.

Surface coating of hydroxyapatite on silk nanofiber through biomineralization using ten times concentrated simulated body fluid and the evaluation for bone regeneration

The biomineralization of hydroxyapatite (HA) on silk nanofiber surface was explored to create organic/inorganic composite scaffold for bone tissue engineering. The porous silk nanofibers matrix was prepared by electrospinning using methanol coagulation bath as a collector and the deposition and coating of HA crystals were proceeded through biomineralization process by immersing the nanofibers in ten times concentrated simulated body fluid (10X SBF). It was found that uniform surface coating of silk nanofibers with HA crystals can be easily obtained by using 10X SBF within short immersion time (60–90 min in this study). The morphological structure of the Silk/HA composite nanofiber was characterized by field emission scanning electron microscopy (FE-SEM) images and structural evidence of HA deposition onto the silk nanofibers were also performed by energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Methylthiazol tetrazolium (MTT) assay confirmed that the cell adhesion and proliferation of osteoblast cells on this composite scaffold was excellent and micro computed tomography (micro-CT) image also showed that better ability of bone regeneration occurred for the Silk/HA composite nanofiber scaffold after 8 weeks implantation. As a result of biological evaluation, the HA coated silk nanofiber scaffold can have a high potential for using in bone tissue regeneration. Open image in new window

PLGA/nHA hybrid nanofiber scaffold as a nanocargo carrier of insulin for accelerating bone tissue regeneration.

The development of tissue engineering in the field of orthopedic surgery is booming. Two fields of research in particular have emerged: approaches for tailoring the surface properties of implantable materials with osteoinductive factors as well as evaluation of the response of osteogenic cells to these fabricated implanted materials (hybrid material). In the present study, we chemically grafted insulin onto the surface of hydroxyapatite nanorods (nHA). The insulin-grafted nHAs (nHA-I) were dispersed into poly(lactide-co-glycolide) (PLGA) polymer solution, which was electrospun to prepare PLGA/nHA-I composite nanofiber scaffolds. The morphology of the electrospun nanofiber scaffolds was assessed by field emission scanning electron microscopy (FESEM). After extensive characterization of the PLGA/nHA-I and PLGA/nHA composite nanofiber scaffolds by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectrometry (EDS), and transmission electron microscopy (TEM), the PLGA/nHA-I and PLGA/nHA (used as control) composite nanofiber scaffolds were subjected to cell studies. The results obtained from cell adhesion, alizarin red staining, and Von Kossa assay suggested that the PLGA/nHA-I composite nanofiber scaffold has enhanced osteoblastic cell growth, as more cells were proliferated and differentiated. The fact that insulin enhanced osteoblastic cell proliferation will open new possibilities for the development of artificial scaffolds for bone tissue regeneration.

Morphological Effects of HA on the Cell Compatibility of Electrospun HA/PLGA Composite Nanofiber Scaffolds

Tissue engineering is faced with an uphill challenge to design a platform with appropriate topography and suitable surface chemistry, which could encourage desired cellular activities and guide bone tissue regeneration. To develop such scaffolds, composite nanofiber scaffolds of nHA and sHA with PLGA were fabricated using electrospinning technique. nHA was synthesized using precipitation method, whereas sHA was purchased. The nHA and sHA were suspended in PLGA solution separately and electrospun at optimized electrospinning parameters. The composite nanofiber scaffolds were characterized by FE-SEM, EDX analysis, TEM, XRD analysis, FTIR, and X-ray photoelectron. The potential of the HA/PLGA composite nanofiber as bone scaffolds in terms of their bioactivity and biocompatibility was assessed by culturing the osteoblastic cells onto the composite nanofiber scaffolds. The results from in vitro studies revealed that the nHA/PLGA composite nanofiber scaffolds showed higher cellular adhesion, proliferation, and enhanced osteogenesis performance, along with increased Ca+2 ions release compared to the sHA/PLGA composite nanofiber scaffolds and pristine PLGA nanofiber scaffold. The results show that the structural dependent property of HA might affect its potential as bone scaffold and implantable materials in regenerative medicine and clinical tissue engineering.

Controlled biomineralization of electrospun poly(ε-caprolactone) fibers to enhance their mechanical properties

Electrospun polymeric fibers have been investigated as scaffolding materials for bone tissue engineering. However, their mechanical properties, and in particular stiffness and ultimate tensile strength, cannot match those of natural bones. The objective of the study was to develop novel composite nanofiber scaffolds by attaching minerals to polymeric fibers using an adhesive material – the mussel-inspired protein polydopamine – as a “superglue”. Herein, we report for the first time the use of dopamine to regulate mineralization of electrospun poly(ε-caprolactone) (PCL) fibers to enhance their mechanical properties. We examined the mineralization of the PCL fibers by adjusting the concentration of HCO3− and dopamine in the mineralized solution, the reaction time and the surface composition of the fibers. We also examined mineralization on the surface of polydopamine-coated PCL fibers. We demonstrated the control of morphology, grain size and thickness of minerals deposited on the surface of electrospun fibers. The obtained mineral coatings render electrospun fibers with much higher stiffness, ultimate tensile strength and toughness, which could be closer to the mechanical properties of natural bone. Such great enhancement of mechanical properties for electrospun fibers through mussel protein-mediated mineralization has not been seen previously. This study could also be extended to the fabrication of other composite materials to better bridge the interfaces between organic and inorganic phases.

In Vitro Osteogenic Differentiation of Human Mesenchymal Stem Cells and In Vivo Bone Formation in Composite Nanofiber Meshes

Tissue engineering has become an alternative method to traditional surgical treatments for the repair of bone defects, and an appropriate scaffold supporting bone formation is a key element in this approach. In the present study, nanofibrous organic and inorganic composite scaffolds containing nano-sized demineralized bone powders (DBPs) with biodegradable poly(L-lactide) (PLA) were developed using an electrospinning process for engineering bone. To assess their biocompatibility, in vitro osteogenic differentiation of human mandible-derived mesenchymal stem cells (hMSCs) cultured on PLA or PLA/DBP composite nanofiber scaffolds were examined. The mineralization of hMSCs cultured with osteogenic supplements on the PLA/DBP nanofiber scaffolds was remarkably greater than on the PLA nanofiber scaffold during the first 14 days of culture but reached the same level after 21 days. The in vivo osteoconductive effect of PLA/DBP nanofibrous scaffolds was further investigated using rats with critical-sized skull defects. Micro-computerized tomography revealed that a greater amount of newly formed bone extended across the defect area in PLA/DBP scaffolds than in the nonimplant and PLA scaffolds 12 weeks after implantation and that the defect size was almost 90% smaller. Therefore, PLA/DBP composite nanofiber scaffolds may serve as a favorable matrix for the regeneration of bone tissue.