PHBV Scaffold Research Articles

Accelerated wound closure rate by hyaluronic acid release from coated PHBV electrospun fiber scaffolds

The enormous potential of electrospun polymer fibers allows for their development in the field of biomaterials for tissue engineering and wound healing. Electrospun fibers based on biodegradable polymers such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) are an ideal material for the production of a biocompatible cell scaffold supporting wound closure and skin regeneration. The aim of this research was to create a fibrous PHBV scaffold supporting the 3D environment for anchoring and proliferation of keratinocytes. Moreover, hyaluronic acid (HA) has been used as a coating on PHBV fibers to improve the wound closure processes. ATR-FTIR results indicated the presence of HA in the PHBV scaffolds and UV–Vis analysis confirmed the release of HA from the fibers over 24h test. Importantly, this release of HA increase keratinocyte activity as well their proliferation leading to accelerated wound closure rate in the scratch tests. The designed HA-coated PHBV scaffolds demonstrate the great potential of surface-modified electrospun polymer fibers for wound healing.

Integration of Bioglass Into PHBV-Constructed Tissue-Engineered Cartilages to Improve Chondrogenic Properties of Cartilage Progenitor Cells.

Background: The Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffold has proven to be a promising three-dimensional (3D) biodegradable and bioactive scaffold for the growth and proliferation of cartilage progenitor cells (CPCs). The addition of Bioglass into PHBV was reported to increase the bioactivity and mechanical properties of the bioactive materials. Methods: In the current study, the influence of the addition of Bioglass into PHBV 3D porous scaffolds on the characteristics of CPC-based tissue-engineered cartilages in vivo were compared. CPCs were seeded into 3D macroporous PHBV scaffolds and PHBV/10% Bioglass scaffolds. The CPC–scaffold constructs underwent 6 weeks in vitro chondrogenic induction culture and were then transplanted in vivo for another 6 weeks to evaluate the difference between the CPC–PHBV construct and CPC–PHBV/10% Bioglass construct in vivo. Results: Compared with the pure PHBV scaffold, the PHBV/10% Bioglass scaffold has better hydrophilicity and a higher percentage of adhered cells. The CPC–PHBV/10%Bioglass construct produced much more cartilage-like tissues with higher cartilage-relative gene expression and cartilage matrix protein production and better biomechanical performance than the CPC–PHBV construct. Conclusion: The addition of Bioglass into 3D PHBV macroporous scaffolds improves the characteristics of CPC-based tissue-engineered cartilages in vivo.

Centella asiatica Extract Potentiates Anticancer Activity in an Improved 3-D PHBV-Composite-CMC A549 Lung Cancer Microenvironment Scaffold

Traditional cell culture makes use of two-dimensional (2-D) surfaces for unnatural characteristics in vitro cell response and growth. To overcome the limitation, 3-D culture models mimicking the cancer microenvironment in vivo are gaining attention. Herein, we investigated an improved composite 3-D biomimetic structure comprising poly(hydroxybutyrate-co-hydroxyvalerate) and carboxymethylcellulose (CMC) (PHBV-co-CMC) for determining the potentiation effects of Centella asiatica extract on lung cancer cells (A549). To improve its biological acceptance characteristics, the 3-D scaffold was infused with low viscosity CMC gel (0.009 ± 0.0004 Pa s) under vacuum pressure. The composite material was left immersed in complete growth media with the presence of cells to determine its optimum day of degradation prior to anti-proliferative (IC50) analysis through 2-D and 3-D cell culture. All scaffolds were found to be sustained for up to 7 days of incubation with breakages ranging from 10 to 70% (w/w). The A549 cell mortality treated with the extract (IC50 5.75 ± 1.0 µg/ml) on both porous 3-D PHBV and composite-CMC scaffolds were 70% higher than the 2-D model (30%) (p < 0.05). Visual assessment on the inner structure of the 3-D scaffold using fluorescent microscopy and scanning electron microscopy showed a scattering number of living cells on the scaffold pores wall and on the CMC gel with a glowing blue color indicating the presence of a livable cells post DAPI dye staining. Therefore, the structure of composite 3-D PHBV scaffold co-CMC produced a potential alternative method of a 3-D cell culture model to study the effectiveness of medicinal plant extracts (e.g. anticancer properties) in which might potentially mimic specific cancerous tissue ex vivo.

Enhanced Crystallinity and Antibacterial of PHBV Scaffolds Incorporated with Zinc Oxide

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) has a great potential in bone repair, but unfortunately, the poor mechanical properties limit its further application. In this work, zinc oxide (ZnO) nanoparticles were incorporated into PHBV porous scaffold fabricated by selective laser sintering technique. It was because ZnO nanoparticles could provide nucleating sites for the orderly stacking of polymer chains, thereby enhancing the crystallinity of PHBV. It was well known that the mechanical properties of PHBV scaffold could be enhanced with the increase of crystallinity. More significantly, the released Zn2+ would combine negatively charged cell membranes of bacterial through electrostatic interaction and consequently destructed the protein structure and resulted in the death of bacterial, which was highly desired in reducing the risk of implant infection. Results indicated that the relative crystallinity of scaffold with 3 wt.% ZnO increased remarkably from 38% to 64% compared to pure PHBV scaffold, which effectively enhanced the compression strength and modulus by 56% and 51.5%, respectively. Moreover, the scaffold had a favorable antibacterial activity. Cell culture experiments proved that the scaffold could promote the cell behaviors. The positive results demonstrated the scaffold may serve as a potential replacement in bone repair.

Aloe Vera-Derived Gel-Blended PHBV Nanofibrous Scaffold for Bone Tissue Engineering.

Today, composite scaffolds fabricated by natural and synthetic polymers have attracted a lot of attention among researchers in the field of tissue engineering, and given their combined properties that can play a very useful role in repairing damaged tissues. In the current study, aloe vera-derived gel-blended poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibrous scaffold was fabricated by electrospinning, and then, PHBV and PHBV gel fabricated scaffolds characterized by scanning electron microscope, protein adsorption, cell attachment, tensile and cell's viability tests. After that, osteogenic supportive property of the scaffolds was studied by culturing of human-induced pluripotent stem cells on the scaffolds under osteogenic medium and evaluating of the common bone-related markers. The results showed that biocompatibility of the PHBV nanofibrous scaffold significantly improved when combined with the aloe vera gel. In addition, higher amounts of alkaline phosphatase activity, mineralization, and bone-related gene and protein expression were detected in stem cells when grown on PHBV-gel scaffold in comparison with those stem cells grown on the PHBV and culture plate. Taken together, it can be concluded that aloe vera gel-blended PHBV scaffold has a great promising osteoinductive potential that can be used as a suitable bioimplant for bone tissue engineering applications to accelerate bone regeneration and also degraded completely along with tissue regeneration.

Molybdenum disulfide nanosheets embedded with nanodiamond particles: co-dispersion nanostructures as reinforcements for polymer scaffolds

The aggregation of low-dimensional nanomaterials restricts their use as reinforcements in polymers. In this study, co-dispersion nanostructures were constructed by embedding nanodiamond (ND) particles into molybdenum disulfide (MoS2) nanosheets, and then were incorporated into poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) bone scaffolds that were fabricated via selective laser sintering. In the nanostructures, octahedral ND particles were sandwiched between adjacent MoS2 nanosheets, which restrained the restacking of the MoS2 nanosheets. Additionally, the MoS2 nanosheets acted as steric hindrance layers, which prevented the aggregation of octahedral ND particles. Experimental results demonstrated that the MoS2 nanosheets and ND particles were evenly dispersed in the PHBV matrix when 1 wt% of MoS2 and 2 wt% of ND were loaded at the same time, while the aggregation occurred when they were loaded individually. As a result, the scaffold with MoS2 and ND loading exhibited a 94% increase in tensile strength and 52% increase in compressive strength compared to a pure PHBV scaffold. The main strengthening mechanisms were crack deflection, crack bridging, crack pinning, and pulling out of MoS2 nanosheets and ND particles. In addition, the scaffold exhibited good cytocompatibility for cell adhesion, growth and spreading, as well as positive viability for cell proliferation.

Enhanced water uptake of PHBV scaffolds with functionalized cellulose nanocrystals

Super hydrophilic scaffolds of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with 3 wt % of acetylated (CNC-Ac) and PEGylated (CNC-PEG) cellulose nanocrystals (CNC) were prepared. PHBV, PHBV/CNC-Ac, and PHBV/CNC-PEG scaffolds were characterized with respect to their morphology by scanning electron microscopy (SEM) and X-ray microtomography. The crystallinity was evaluated by differential scanning calorimetry (DSC) and the mechanical properties by uniaxial compression tests. The presence of residual solvent was identified by gas chromatography (GC), wettability measured by static contact angle and aqueous adsorption by gravimetry. All the scaffolds showed porous morphology, being that, for neat PHBV the morphology was more regular with oriented pores. The porosity was reduced by 26% with the introduction of CNC-Ac and CNC-PEG, and the compression modulus increased by 25% and 72% for PHBV/CNC-Ac and PHBV/CNC-PEG scaffolds, respectively, compared to neat PHBV. Even with lower porosities, PHBV/CNC-Ac and PHBV/CNC-PEG adsorbed 16% and 67% more water than PHBV scaffold, following the intraparticle diffusion model for all the samples. No residual solvents were found and the crystallinity was slightly increased upon addition of CNC-Ac and CNC-PEG. Therefore, the addition of CNC-Ac and CNC-PEG can improve both compressive modulus and water uptake, turning PHBV nanocomposite scaffolds suitable for tissue engineering applications.

Water Uptake in PHBV/Wollastonite Scaffolds: A Kinetics Study

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a widely studied polymer and it has been found that porous PHBV materials are suitable for substrates for cell cultures. A crucial factor for scaffolds designed for tissue engineering is the water uptake. This property influences the transport of water and nutrients into the scaffold, which promotes cell growth. PHBV has significant hydrophobicity, which can harm the production of cells. Thus, the addition of α-wollastonite (WOL) can modify the PHBV scaffold’s water uptake. To our knowledge, a kinetics study of water uptake of α-wollastonite phase powder and the PHBV matrix has not been reported. In this work, PHBV and WOL, (PHBV/WOL) films were produced with 0, 5, 10, and 20 wt % of WOL. Films were characterized, and the best concentrations were chosen to produce PHBV/WOL scaffolds. The addition of WOL in concentrations up to 10 wt % increased the cell viability of the films. MTT analysis showed that PHBV/5%WOL and PHBV/10%WOL obtained cell viability of 80% and 98%, respectively. Therefore, scaffolds with 0, 5 and 10 wt % of WOL were fabricated by thermally induced phase separation (TIPS). Scaffolds were characterized with respect to morphology and water uptake in assay for 65 days. The scaffold with 10 wt % of WOL absorbed 44.1% more water than neat PHBV scaffold, and also presented a different kinetic mechanism when compared to other samples. Accordingly, PHBV/WOL scaffolds were shown to be potential candidates for biological applications.

Deformation behavior of porous PHBV scaffold in compression: A finite element analysis study

Macroscopic mechanical properties of porous PHBV bone TE scaffolds have been well studied. However, their mechanical behavior at microscopic level has yet to be explored. In this study, the micro-mechanical behavior of a PHBV bone scaffold under compression was investigated using a numerical method that combines micro-computed tomography (μ-CT) and finite element analysis (FEA). It was found that the use of a linear-elastic model resulted in an overestimation of the stiffness of the scaffold, whereas a more realistic estimation of the scaffold's deformation behavior was obtained by utilizing a bilinear material model. The onset of plastic deformation occurred in the very early stage of loading resulting in significantly reduced stiffness of the scaffold. The non-uniform and arbitrary microstructure of the scaffold led to a heterogeneous stress distribution within the porous construct, which was subjected to a mixture of compressive and tensile stresses. Nevertheless, the resultant stress contours showed that the scaffold experienced primarily elastic deformation when it was loaded up to 0.003 strain, while localized plastic deformation occurred at sharp corners and necked regions of the micro-struts. The scaffold expanded slightly in the horizontal direction as it was compressed and the change in geometries of pores within the scaffold was insignificant. The proposed method provides a valuable tool to study the localized mechanical behavior of bone scaffolds in micrometer scale with arbitrary porous architecture. This approach could prove highly useful for guiding the fabrication of scaffolds that have anatomy specific mechanical properties and porous architecture.

Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) improved osteogenic differentiation of the human induced pluripotent stem cells while considered as an artificial extracellular matrix.

Cocell polymers can be the best implants for replacing bone defects in patients. The pluripotent stem cells produced from the patient and the nanofibrous polymeric scaffold that can be completely degraded in the body and its produced monomers could be also usable are the best options for this implant. In this study, electrospun poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers were fabricated and characterized and then osteogenic differentiation of the human-induced pluripotent stem cells (iPSCs) was investigated while cultured on PHBV scaffold. MTT results showed that cultured iPSCs on PHBV proliferation were increased compared to those cultured on tissue culture polystyrene (TCPS) as the control. Alkaline phosphatase (ALP) activity and calcium content were also significantly increased in iPSCs cultured on PHBV compared to the cultured on TCPS under osteogenic medium. Gene expression evaluation demonstrated that Runx2, collagen type I, ALP, osteonectin, and osteocalcin were upregulated in iPSCs cultured on PHBV scaffold in comparison with those cultured on TCPS for 2 weeks. Western blot analysis have shown that osteocalcin and osteopontin expression as two major osteogenic markers were increased in iPSCs cultured on PHBV scaffold. According to the results, nanofiber-based PHBV has a promising potential to increase osteogenic differentiation of the stem cells and iPSCs-PHBV as a cell-co-polymer construct demonstrated that has a great efficiency for use as a bone tissue engineered bioimplant.

Synthesis, microstructure, and mechanical behaviour of a unique porous PHBV scaffold manufactured using selective laser sintering.

Selective Laser Sintering (SLS) is a promising technique for manufacturing bio-polymer scaffolds used in bone tissue engineering applications. Conventional scaffolds made using SLS have complex engineered architectures to introduce adequate porosity and pore interconnectivity. This study presents an alternative approach to manufacture scaffolds via SLS without using pre-designed architectures. In this work, a SLS process was developed for fabricating interconnected porous biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffolds with large surface areas and relative porosities of up to 80%. These characteristics provide great potential to enhance cell attachment inside the scaffolds. The scaffold microstructure was dependent on the laser energy density (LED) during the SLS process. An increase in LED led to scaffolds with higher relative densities, stronger inter-layer connections, and a reduced quantity of residual powder trapped inside the pores. An increase in relative density from 20.3% to 41.1% resulted in a higher maximum compressive modulus and strength of 36.4 MPa and 6.7 MPa, respectively.

Fabrication and evaluation of nanofibrous polyhydroxybutyrate valerate scaffolds containing hydroxyapatite particles for bone tissue engineering

ABSTRACTTissue engineering is a new approach for regeneration of damaged tissues. The current clinical methods such as autograft and allograft transplantation are not effective for repairing bone damages, mainly due to the limited available sources and the donor-site side effects. In this research, the nanocomposite poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/nano hydroxyapatite (nHA) scaffolds with different nHA ratios for bone regeneration were utilized. The diameter and porosity of scaffolds were approximately 200 nm and 74%, respectively. The degradability test of the scaffolds suggests a low degradation rate with total degradation of 30% after 3 months. Cytotoxicity result showed that cultured osteoblast cells (MC3T3) on nanocomposite scaffolds had superiority in terms of higher proliferation and attachment in comparison with PHBV scaffold. The protein expression of alkaline phosphatase illustrated that nanofibrous scaffold containing hydroxyapatite had the highest alkaline phosphatase activities as a result of better proliferation. These results recommend that PHBV/nHA scaffolds are suitable candidates for bone tissue engineering.

Enhanced proliferation and mineralization of human fetal osteoblast cells on PHBV-bredigite nanofibrous scaffolds

In this study, bredigite (Ca7MgSi4O16) nanoparticles were incorporated into the poly (3-hydroxybutyrate-co-3-hydroxyvalerate) nanofibers using electrospinning, to produce scaffold materials for bone tissue engineering. The morphological and physicochemical properties of the bredigite (0, 5, 10 and 15% wt) containing scaffolds were studied by using field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy. The assessment of mechanical properties revealed that the addition of the nanoparticles improved the tensile strength and young modulus of the scaffolds. In vitro bioactivity evaluation performed in the simulated body fluid (SBF) demonstrated the formation of apatite layer on the surface of composite nanofibers after immersion in SBF. Studies on cell–scaffolds interaction were carried out by culturing human fetal osteoblast (hFOB) cells on the scaffolds, which revealed the higher cells proliferation and mineral deposition on PHBV-bredigite scaffolds compared to PHBV scaffolds. Cell differentiation identified by alkaline phosphatase activity was significantly higher on PHBV-bredigite scaffold than on PHBV scaffold. All of these results suggest that the produced PHBV-bredigite nanofibrous scaffold would be a promising candidate as an osteoconductive material for bone tissue regeneration applications.

Polyhydroxybutyrate-co-hydroxyvalerate structures loaded with adipose stem cells promote skin healing with reduced scarring

Currently available skin substitutes are still associated with a range of problems including poor engraftment resulting from deficient vascularization, and excessive scar formation, among others. Trying to overcome these issues, this work proposes the combination of poly(3-hydroxybutyrate-co-hydroxyvalerate) (PHBV) structures with adipose-derived stem cells (ASCs) to offer biomechanical and biochemical signaling cues necessary to improve wound healing in a full-thickness model. PHBV scaffold maintained the wound moisture and demonstrated enough mechanical properties to withstand wound contraction. Also, exudate and inflammatory cell infiltration enhanced the degradation of the structure, and thus healing progression. After 28days all the wounds were closed and the PHBV scaffold was completely degraded. The transplanted ASCs were detected in the wound area only at day 7, correlating with an up-regulation of VEGF and bFGF at this time point that consequently led to a significant higher vessel density in the group that received the PHBV loaded with ASCs. Subsequently, the dermis formed in the presence of the PHBV loaded with ASCs possesses a more complex collagen structure. Additionally, an anti-scarring effect was observed in the presence of the PHBV scaffold indicated by a down-regulation of TGF-β1 and α-SMA together with an increase of TGF-β3, when associated with ASCs. These results indicate that although PHBV scaffold was able to guide the wound healing process with reduced scarring, the presence of ASCs was crucial to enhance vascularization and provide a better quality neo-skin. Therefore, we can conclude that PHBV loaded with ASCs possesses the necessary bioactive cues to improve wound healing with reduced scarring.

Design of Oriented Porous PHBV Scaffold as a Neural Guide

The aim of this study was to produce an oriented biodegradable poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nerve guide. Oriented porous micropatterned artificial nerve guide designed onto the micro-patterned silicon wafers, then their surfaces modified with to oxygen plasma for cell attachment increasing. Afterwards, the neural guides were evaluated by microscopic, structural, physical, and mechanical analyses, and cell culture assays with Schwann cells. Results of structural, physical, and mechanical analyses showed a good resilience and compliance with movement as a neural graft. Cellular experiments showed a better cell adhesion, growth, and proliferation inside the plasma-modified neural guides compared to un-modified ones, also Schwann cells were well attached on plasma-modified surface. This neural guide appears to have the right organization for testing in vivo nerve tissue engineering studies.

Unrestricted Somatic Stem Cells Loaded in Nanofibrous Scaffolds as Potential Candidate for Skin Regeneration

The authors have demonstrated the ability of cord blood–derived unrestricted somatic stem cells (USSCs) and gelatin-modified PHBV scaffold to promote skin regeneration. The scaffolds were designed by electrospinning method and evaluated by different analyses. Results of physical and mechanical analyses also were shown a good resilience as a skin graft. In animal model; all groups excluding the control group exhibited the most pronounced effect on wound closure, with the statistically significant improvement in wound healing being seen at post-operative day 21. Thus, the grafting of nanofibrous scaffold loaded with USSC showed better results during the healing process of skin defects in rat models.

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-based nanofibrous scaffolds to support functional esophageal epithelial cells towards engineering the esophagus

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and PHBV–gelatin were electrospun to obtain defect-free nanofibers by optimizing various process and solution parameters. Tensile strength, Young’s modulus, and wettability of PHBV–gelatin nanofibrous scaffold were determined and compared with PHBV nanofibrous scaffold. Our results demonstrate that PHBV–gelatin nanofibers exhibited higher tensile strength and Young’s modulus than the PHBV nanofibers. Human esophageal epithelial cells (HEEpiC) were cultured on PHBV and PHBV–gelatin nanofiber showed better cell proliferation in PHBV nanofibrous scaffold than the PHBV–gelatin scaffold after 7 days of culture. HEEpiC cultured on PHBV and PHBV–gelatin nanofibrous scaffold exhibited characteristic epithelial cobblestone morphology after 3 days of culture. Further, the HEEpiC extracellular matrix (ECM) proteins (collagen type IV and laminin) and phenotypic marker proteins (cytokeratin-4 and 14) expressions were significantly higher in PHBV–gelatin nanofibrous scaffold than the PHBV nanofiber scaffold. However, the long-term stability and functional state of the cells on the PHBV scaffold give it an edge over the blend scaffolds. Thus, PHBV-based nanofibrous scaffolds could be explored further as ECM substitutes for the regeneration of esophageal tissue.

PHBV/PAM Scaffolds with Local Oriented Structure through UV Polymerization for Tissue Engineering

Locally oriented tissue engineering scaffolds can provoke cellular orientation and direct cell spread and migration, offering an exciting potential way for the regeneration of the complex tissue. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffolds with locally oriented hydrophilic polyacrylamide (PAM) inside the macropores of the scaffolds were achieved through UV graft polymerization. The interpenetrating PAM chains enabled good interconnectivity of PHBV/PAM scaffolds that presented a lower porosity and minor diameter of pores than PHBV scaffolds. The pores with diameter below 100 μm increased to 82.15% of PHBV/PAM scaffolds compared with 31.5% of PHBV scaffolds. PHBV/PAM scaffold showed a much higher compressive elastic modulus than PHBV scaffold due to PAM stuffing. At 5 days of culturing, sheep chondrocytes spread along the similar direction in the macropores of PHBV/PAM scaffolds. The locally oriented PAM chains might guide the attachment and spreading of chondrocytes and direct the formation of microfilaments via contact guidance.

Regeneration of Full-Thickness Skin Defects Using Umbilical Cord Blood Stem Cells Loaded into Modified Porous Scaffolds

In this study, we have demonstrated the ability of cord blood (CB)-derived unrestricted somatic stem cells (USSCs) and chitosan-modified poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffold to promote skin regeneration. Afterward, the scaffolds were evaluated by structural, microscopic, physical, and mechanical assays and cell culture analyses. Results of structural, physical, and mechanical analyses also showed a good resilience and compliance with movement as a skin graft. Cellular experiments showed a better cell adhesion, growth, and proliferation inside the modified scaffolds compared with unmodified ones. In animal models with histological examinations, all groups, excluding the control group especially the groups treated with stem cells, exhibited the most pronounced effect on wound closure, with the statistically significant improvement in wound healing being seen at postoperative day 21. These data suggest that chitosan-modified PHBV scaffold loaded with CB-derived USSCs could significantly contribute to wound repair and be potentially used in the tissue engineering.

The healing effect of unrestricted somatic stem cells loaded in collagen-modified nanofibrous PHBV scaffold on full-thickness skin defects

Unrestricted somatic stem cells (USSCs) loaded in nanofibrous PHBV scaffold can be used for skin regeneration when grafted into full-thickness skin defects of rats. Nanofibrous PHBV scaffolds were designed using electrospinning method and then, modified with the immobilized collagen via the plasma method. Afterward, the scaffolds were evaluated using scanning electron microscopy, physical and mechanical assays. In this study; nanofibrous PHBV scaffolds loaded with and without USSCs were grafted into the skin defects. The wounds were subsequently investigated at 21 days after grafting. Results of mechanical and physical analyses showed good resilience and compliance to movement as a skin graft. In animal models; all study groups excluding the control group exhibited the most pronounced effect on wound closure, with the statistically significant improvement in wound healing being seen on post-operative Day 21. Histological and immunostaining examinations of healed wounds from all groups, especially the groups treated with stem cells, showed a thin epidermis plus recovered skin appendages in the dermal layer. Thus, the graft of collagen-coated nanofibrous PHBV scaffold loaded with USSC showed better results during the healing process of skin defects in rat model.