Fibrous Scaffolds Research Articles

Novel polypeptide composite fibrous scaffold with internal chemical boundary

Novel polypeptide composite fibrous scaffold with internal chemical boundary

A 3D-printed micro-perfused culture device with embedded 3D fibrous scaffold for enhanced biomimicry

Additive manufacturing has rapidly revolutionized the medical sectors since it is a versatile, cost-effective, assembly free technique with the ability to replicate geometrically complicated features. Some of the widely reported applications include the printing of scaffolds, implants, or microfluidic devices. In this study, a 3D-printed micro-perfused culture (MPC) device embedded with a nanofibrous scaffold was designed to create an integrated micro-perfused 3D cell culture environment for living cells. The addition of 3D fibrous scaffold onto the microfluidic chip was to provide a more physiologically relevant microenvironment for cell culture studies. Stereolithography was adopted in this study as this technique obviates excessive preassembly and bonding steps, which would otherwise be needed in conventional microfluidic fabrication. Huh7.5 hepatocellular carcinoma cells were used as model cells for this platform since liver cells experience similar perfused microenvironment. Preliminary cell studies revealed that gene expressions of albumin (ALB) and cytochrome P450 isoform (CYP3A7) were found to be significantly upregulated on the 3D-printed MPC device as compared to the static counterpart. Taken together, the 3D-printed MPC device is shown to be a physiologically relevant platform for the maintenance of liver cells. The device and printing technique developed in this study is highly versatile and tailorable to mimic local in vivo microenvironment needs of various tissues, which could be studied in future.  

Mussel bioinspired, silver-coated and insulin-loaded mesoporous polydopamine nanoparticles reinforced hyaluronate-based fibrous hydrogel for potential diabetic wound healing

Diabetes wounds take longer to heal due to extended inflammation, decreased angiogenesis, bacterial infection, and oxidative stress. These factors underscore the need for biocompatible and multifunctional dressings with appropriate physicochemical and swelling properties to accelerate wound healing. Herein, insulin (Ins)-loaded, and silver (Ag) coated mesoporous polydopamine (mPD) nanoparticles were synthesized (Ag@Ins-mPD). The nanoparticles were dispersed into polycaprolactone/methacrylated hyaluronate aldehyde dispersion, electrospun to form nanofibers, and then photochemically crosslinked to form a fibrous hydrogel. The nanoparticle, fibrous hydrogel, and nanoparticle-reinforced fibrous hydrogel were characterized for their morphological, mechanical, physicochemical, swelling, drug-release, antibacterial, antioxidant, and cytocompatibility properties. The diabetic wound reconstruction potential of nanoparticle-reinforced fibrous hydrogel was studied using BALB/c mice. The results indicated that Ins-mPD acted as a reductant to synthesize Ag nanoparticles on their surface, held antibacterial and antioxidant potential, and their mesoporous properties are crucial for insulin loading and sustained release. The nanoparticle-reinforced scaffolds were uniform in architecture, porous, mechanically stable, showed good swelling, and possessed superior antibacterial, and cell-responsive properties. Furthermore, the designed fibrous hydrogel scaffold demonstrated good angiogenic, anti-inflammatory, increased collagen deposition, and faster wound repair capabilities, therefore, it could be used as a potential candidate for diabetic wound treatment.

Aminosilane Functionalized Aligned Fiber PCL Scaffolds for Peripheral Nerve Repair.

Silane modification is a simple and cost-effective tool to modify existing biomaterials for tissue engineering applications. Aminosilane layer deposition has previously been shown to control NG108-15 neuronal cell and primary Schwann cell adhesion and differentiation by controlling deposition of ─NH2 groups at the submicron scale across the entirety of a surface by varying silane chain length. This is the first study toreport depositing 11-aminoundecyltriethoxysilane (CL11) onto aligned Polycaprolactone (PCL) scaffolds for peripheral nerve regeneration. Fibers are manufactured via electrospinning and characterized using water contact angle measurements, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Confirmed modified fibers are investigated using in vitro cell culture of NG108-15 neuronal cells and primary Schwann cells to determine cell viability, cell differentiation, and phenotype. CL11-modified fibers significantly support NG108-15 neuronal cell and Schwann cell viability. NG108-15 neuronal cell differentiation maintains Schwann cell phenotype compared to unmodified PCL fiber scaffolds. 3D ex vivo culture of Dorsal root ganglion explants (DRGs) confirms further Schwann cell migration and longer neurite outgrowth from DRG explants cultured on CL11 fiber scaffolds compared to unmodified scaffolds. Thus, a reproducible and cost-effective tool is reported to modify biomaterials with functional amine groups that can significantly improve nerve guidance devices and enhance nerve regeneration.

Fabrication of konjac glucomannan‐silk fibroin based biomimetic scaffolds for improved vascularization and soft tissue engineering applications

AbstractThe biomimetic scaffolds were fabricated using two natural biopolymers; Konjac glucomannan (KGM) and Silk fibroin (SF). The various proportions of KGM (1%) and SF (1%–2%) solutions were cross‐linked using citric acid as a cross linker and then lyophilized to prepare the fibrous scaffolds. The physicochemical properties of the KGM/SF scaffolds were investigated using FT‐IR analysis, TGA analysis, SEM, porosity, swelling, in vitro biodegradation, and mechanical characterization. FTIR spectra revealed the presence of characteristic functional moieties in the KGM/SF scaffolds. The improved thermal stability was observed for KGM/SF scaffolds compared to the control. The SEM images revealed that the scaffolds exhibited a porous morphology. The biodegradation of KGM/SF scaffolds was almost 77% until day 21, showing the biodegradable nature of the KGM/SF scaffolds. The compression strength of KGM/SF scaffolds was significantly higher than the KGM scaffold and eligible for soft tissue engineering. The KGM/SF scaffolds were further characterized by in vitro cell viability and cell attachment in fibroblast cells, demonstrating the non‐toxicity of scaffolds. Finally, in vivo CAM assay was successfully performed and determined the efficacy of KGM/SF scaffolds in vascularization. Overall, the results demonstrated that the KGM/SF scaffolds are biocompatible and capable of promoting vascularization in tissue engineering and biomedical applications.

Bio-Enhanced Neoligaments Graft Bearing FE002 Primary Progenitor Tenocytes: Allogeneic Tissue Engineering & Surgical Proofs-of-Concept for Hand Ligament Regenerative Medicine.

Hand tendon/ligament structural ruptures (tears, lacerations) often require surgical reconstruction and grafting, for the restauration of finger mechanical functions. Clinical-grade human primary progenitor tenocytes (FE002 cryopreserved progenitor cell source) have been previously proposed for diversified therapeutic uses within allogeneic tissue engineering and regenerative medicine applications. The aim of this study was to establish bioengineering and surgical proofs-of-concept for an artificial graft (Neoligaments Infinity-Lock 3 device) bearing cultured and viable FE002 primary progenitor tenocytes. Technical optimization and in vitro validation work showed that the combined preparations could be rapidly obtained (dynamic cell seeding of 105 cells/cm of scaffold, 7 days of co-culture). The studied standardized transplants presented homogeneous cellular colonization in vitro (cellular alignment/coating along the scaffold fibers) and other critical functional attributes (tendon extracellular matrix component such as collagen I and aggrecan synthesis/deposition along the scaffold fibers). Notably, major safety- and functionality-related parameters/attributes of the FE002 cells/finished combination products were compiled and set forth (telomerase activity, adhesion and biological coating potentials). A two-part human cadaveric study enabled to establish clinical protocols for hand ligament cell-assisted surgery (ligamento-suspension plasty after trapeziectomy, thumb metacarpo-phalangeal ulnar collateral ligamentoplasty). Importantly, the aggregated experimental results clearly confirmed that functional and clinically usable allogeneic cell-scaffold combination products could be rapidly and robustly prepared for bio-enhanced hand ligament reconstruction. Major advantages of the considered bioengineered graft were discussed in light of existing clinical protocols based on autologous tenocyte transplantation. Overall, this study established proofs-of-concept for the translational development of a functional tissue engineering protocol in allogeneic musculoskeletal regenerative medicine, in view of a pilot clinical trial.

Fabrication of a Smart Fibrous Biomaterial That Harbors an Active TGF-β1 Peptide: A Promising Approach for Cartilage Regeneration.

The regeneration of articular cartilage remains a serious problem in various pathological conditions such as osteoarthritis, due to the tissue's low self-healing capacity. The latest therapeutic approaches focus on the construction of biomaterials that induce cartilage repair. This research describes the design, synthesis, and investigation of a safe, "smart", fibrous scaffold containing a genetically incorporated active peptide for chondrogenic induction. While possessing specific sequences and the respective mechanical properties from natural fibrous proteins, the fibers also incorporate a Transforming Growth Factor-β1 (TGF-β1)-derived peptide (YYVGRKPK) that can promote chondrogenesis. The scaffold formed stable porous networks with shear-thinning properties at 37 °C, as shown by SEM imaging and rheological characterization, and were proven to be non-toxic to human dental pulp stem cells (hDPSCs). Its chondrogenic capacity was evidenced by a strong increase in the expression of specific chondrogenesis gene markers SOX9, COL2, ACAN, TGFBR1A, and TGFBR2 in cells cultured on "scaffold-TGFβ1" for 21 days and by increased phosphorylation of intracellular signaling proteins Smad-2 and Erk-1/2. Additionally, intense staining of glycosaminoglycans was observed in these cells. According to our results, "scaffold-TGFβ1" is proposed for clinical studies as a safe, injectable treatment for cartilage degeneration.

Micromechanical homogenization of a hydrogel-filled electrospun scaffold for tissue-engineered epicardial patching of the infarcted heart: a feasibility study

AbstractFor tissue engineering applications, accurate prediction of the effective mechanical properties of tissue scaffolds is critical. Open and closed cell modelling, mean-field homogenization theory, and finite element (FE) methods are theories and techniques currently used in conventional homogenization methods to estimate the equivalent mechanical properties of tissue-engineering scaffolds. This study aimed at developing a formulation to link the microscopic structure and macroscopic mechanics of a fibrous electrospun scaffold filled with a hydrogel for use as an epicardial patch for local support of the infarcted heart. The macroscopic elastic modulus of the scaffold was predicted to be 0.287 MPa with the FE method and 0.290 MPa with the closed-cell model for the realistic fibre structure of the scaffold, and 0.108 MPa and 0.540 MPa with mean-field homogenization for randomly oriented and completely aligned fibres. The homogenized constitutive description of the scaffold was implemented for an epicardial patch in a FE model of a human cardiac left ventricle to assess the effects of patching on myocardial mechanics and ventricular function in the presence of an infarct. Epicardial patching was predicted to reduce maximum myocardial stress in the infarcted LV from 19 kPa (no patch) to 9.5 kPa (patch) and to marginally improve the ventricular ejection fraction from 40% (no patch) to 43% (patch). This study demonstrates the feasibility of homogenization techniques to represent complex multiscale structural features in a simplified but meaningful and effective manner.

Need for innovation: laser sutures

In this modern era there is dire need of awareness regarding sutureless surgical procedures. Globally 310 million surgeries are performed each year1. Using thread and needle for suturing is still as common as using legs to walk. This method is not near to ideal because of risk of contamination, infections, scar marks, needle trauma, and reopening of tissues if the stitches are not held tight2. The prevention of wound infections after surgical procedures is of great interest for every surgical discipline, in order to improve the quality of patient care. And the best way to prevent suture-related complications is to have sutureless procedures. A number of sutureless methods have developed over the time which includes fibrin glue, cyanoacrylates, scaffolds and bio-inspired adhesives3. The sutureless technique which is receiving increasing attention is Photochemical Tissue Bonding (PTB), which can also be called laser sutures. PTB is a novel tissue repair technique that causes the proteins on tissue surfaces to crosslink by using visible light and a photosensitizing dye. This technique has been successfully demonstrated in a number of tissue repair models4. This suture-replacement technique is able to close incisions nearly instantaneously without damaging tissue. It gives minimum scar, is time saving, has more accuracy, causes less infections and is less user dependent as compared with typical sutures. This technique does not provide promising results on the skin but also has been tested for vascular and nervous repairs5. Therefore I think it’s high time that surgeons should consider using this in their practice. Ethical approval None. Sources of funding None. Author contribution Misbah Kaleem: Conception of work along with final draft. Musaddiq Kaleem: Editing draft and reviewed article. Conflict of interest disclosure The authors declare that they have no financial conflict of interest with regard to the content of this report. Research registration unique identifying number (UIN) None. Guarantor None.

Calcium Trimetaphosphate-Loaded Electrospun Poly(Ester Urea) Nanofibers for Periodontal Tissue Engineering.

The objective of this research was to create and appraise biodegradable polymer-based nanofibers containing distinct concentrations of calcium trimetaphosphate (Ca-TMP) for periodontal tissue engineering. Poly(ester urea) (PEU) (5% w/v) solutions containing Ca-TMP (15%, 30%, 45% w/w) were electrospun into fibrous scaffolds. The fibers were evaluated using SEM, EDS, TGA, FTIR, XRD, and mechanical tests. Degradation rate, swelling ratio, and calcium release were also evaluated. Cell/Ca-TMP and cell/scaffold interaction were assessed using stem cells from human exfoliated deciduous teeth (SHEDs) for cell viability, adhesion, and alkaline phosphatase (ALP) activity. Analysis of variance (ANOVA) and post-hoc tests were used (α = 0.05). The PEU and PEU/Ca-TMP-based membranes presented fiber diameters at 469 nm and 414-672 nm, respectively. Chemical characterization attested to the Ca-TMP incorporation into the fibers. Adding Ca-TMP led to higher degradation stability and lower dimensional variation than the pure PEU fibers; however, similar mechanical characteristics were observed. Minimal calcium was released after 21 days of incubation in a lipase-enriched solution. Ca-TMP extracts enhanced cell viability and ALP activity, although no differences were found between the scaffold groups. Overall, Ca-TMP was effectively incorporated into the PEU fibers without compromising the morphological properties but did not promote significant cell function.

Antimicrobial Effects of Mouse Adipose-Derived Mesenchymal Stem Cells Encapsulated in Collagen-Fibrin Hydrogel Scaffolds on Bacteroides fragilis Wound Infection in vivo.

Anaerobes are the causative agents of many wound infections. B. fragilis is the most prevalent endogenous anaerobic bacterium causes a wide range of diseases, including wound infections. This study aimed to assess the antibacterial effect of mouse AD-MSCs encapsulated in CF hydrogel scaffolds on B. fragilis wound infection in an animal model. Stem cells were extracted from mouse adipose tissue and confirmed by surface markers using flow cytometry analysis. The possibility of differentiation of stem cells into osteoblast and adipocyte cells was also assessed. The extracted stem cells were encapsulated in the CF scaffold. B. fragilis wound infection was induced in rats, and then following 24 h, collagen and fibrin-encapsulated MSCs were applied to dress the wound. One week later, a standard colony count test monitored the bacterial load in the infected rats. MSCs were characterized as positive for CD44, CD90, and CD105 markers and negative for CD34, which were able to differentiate into osteoblast and adipocyte cells. AD-MSCs encapsulated with collagen and fibrin scaffolds showed ameliorating effects on B. fragilis wound infection. Additionally, AD-MSCs with a collagen scaffold (54 CFU/g) indicated a greater effect on wound infection than AD-MSCs with a fibrin scaffold (97 CFU/g). The combined CF scaffold demonstrated the highest reduction in colony count (the bacteria load down to 29 CFU/g) in the wound infection. Our findings reveal that the use of collagen and fibrin scaffold in combination with mouse AD-MSCs is a promising alternative treatment for B. fragilis.

Well-ordered and visual poly(ε-caprolactone) composite fibrous membranes for the treatment of skin wounds

Three dimensional (3D) printing near-field electrospinning (NFES) process is a robust method to fabricate fibrous membranes by depositing solid nanofibers in a direct, continuous and controlled manner. In this study, poly(ε-caprolactone) (PCL) solutions were electrospun into composite fibrous membranes with an ordered geometric pore structure by the 3D printing NFES technique. The bioceramic hardystonite (Ca2ZnSi2O7, ZnCS) was added to the PCL fibrous membranes to stimulate epithelial cell and fibroblast proliferation, and adhesion. Meanwhile, the fluorescent material of tetraphenylene (TPE) with easy identification, high sensitivity, and real-time response was added to the PCL fibrous membrane to better observe the wound healing process. The magnitude of the electric field strength and distribution of a single-needle near-field electrospinning system is studied based on the size of the actual device. Furthermore, we analyzed the effect of voltage, distance, and position on the electric field strength based on the simulation results. The results indicated that the composite scaffold was nontoxic, and the cells could adhere, proliferate and differentiate effectively on the composite fibrous membrane scaffold, which could effectively promote wound healing. This PCL/ZnCS/TPE composite fibrous membrane with a controllable structure and pore size is suitable for tissue engineering and medical wound dressing.

Air-jet spun PHBV/PCL blend tissue engineering scaffolds exhibit improved mechanical properties and cell proliferation

This study aimed to optimize the preparation parameters for air-jet spun blended poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and polycaprolactone (PCL) submicron fibrous scaffolds. Blends of PHBV and PCL were made using different weight ratios of polymers and examined for their mechanical, morphological, and biological properties. The 50/50 ratio PHBV/PCL blend scaffolds showed better overall mechanical properties compared to the scaffolds with higher PHBV content and provided better cell attachment and proliferation compared to PCL scaffolds. The incorporation of PCL improved the degree of crystallinity, thermal stability, and mechanical properties of PHBV/PCL blend scaffolds. In vivo subcutaneous implantation and subsequent histological analysis of the implanted scaffolds indicated that the scaffolds were compatible with animal tissues. The findings show that air-jet spun PHBV/PCL blended scaffolds in a 50/50 ratio can be employed in many tissue engineering applications.

POLYCAPROLACTONE FIBER-BASED BOVINE DENDRITIC CELL DEVELOPMENT AND THREE- DIMENSIONAL CULTURE IN VITRO

Two-dimensional (2D) cell culture systems are normally used for in vitro experiments. These systems have some drawbacks which affect results of in vitro experiments because cultured cells have different morphology and physiological properties comparing to in vivo models. Therefore, there are current technique to develop three-dimensional (3D) cell culture systems which are closer to the environment in real tissues. In our study, we used polycaprolactone fiber scaffold for culture of bovine monocytes to develop dendritic cells (DCs) from those cells. Cultured monocytes in the polycaprolactone nanofiber scaffold differentiated to DCs. The differentiated DCs showed a 3D structure in the scaffold. These results suggest that this method is suitable for the development of DCs in a manner of three-dimension. These method is perspective for bovine cell culture and has advantages compare to conventional 2D culture systems.

Wound healing performance of electrospun PVA/70S30C bioactive glass/Ag nanoparticles mats decorated with curcumin: In vitro and in vivo investigations

Biocompatible fibrous scaffold containing polyvinyl alcohol (PVA), 70S30C bioactive glass (BG), silver (Ag) nanoparticles and curcumin (Cur) was fabricated through electrospinning method. Scanning electron microscope (SEM) and Field emission scanning electron microscopy (FESEM) were employed to investigate the morphological characteristics of the scaffolds. In addition, biodegradability, hydrophilicity, and contact angle were studied as criteria for evaluating physical properties of the scaffolds. Tensile strength was reported to be 0.971 ± 0.093 MPa. Also, the viability of fibroblasts after 7 days of cell culture was 93.58 ± 1.36 %. The antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria was illustrated using inhibition zones of 13.12 ± 0.69 and 14.21 ± 1.37 mm, respectively. Histological results revealed that tissue regeneration after 14 days of surgery was much higher for the dressing group compared to the blank group. According to the obtained results, the authors introduce the PVA-BG-Ag-Cur scaffold as a promising candidate for skin tissue engineering applications.

Electrospun decellularized extracellular matrix scaffolds promote the regeneration of injured neurons

Traumatic injury to the spinal cord (SCI) causes the transection of neurons, formation of a lesion cavity, and remodeling of the microenvironment by excessive extracellular matrix (ECM) deposition and scar formation leading to a regeneration-prohibiting environment. Electrospun fiber scaffolds have been shown to simulate the ECM and increase neural alignment and neurite outgrowth contributing to a growth-permissive matrix. In this work, electrospun ECM-like fibers providing biochemical and topological cues are implemented into a scaffold to represent an oriented biomaterial suitable for the alignment and migration of neural cells in order to improve spinal cord regeneration. The successfully decellularized spinal cord ECM (dECM), with no visible cell nuclei and dsDNA content < 50 ng/mg tissue, showed preserved ECM components, such as glycosaminoglycans and collagens. Serving as the biomaterial for 3D printer-assisted electrospinning, highly aligned and randomly distributed dECM fiber scaffolds (< 1 µm fiber diameter) were fabricated. The scaffolds were cytocompatible and supported the viability of a human neural cell line (SH-SY5Y) for 14 days. Cells were selectively differentiated into neurons, as confirmed by immunolabeling of specific cell markers (ChAT, Tubulin ß), and followed the orientation given by the dECM scaffolds. After generating a lesion site on the cell-scaffold model, cell migration was observed and compared to reference poly-ε-caprolactone fiber scaffolds. The aligned dECM fiber scaffold promoted the fastest and most efficient lesion closure, indicating superior cell guiding capabilities of dECM-based scaffolds. The strategy of combining decellularized tissues with controlled deposition of fibers to optimize biochemical and topographical cues opens the way for clinically relevant central nervous system scaffolding solutions.

Dual-bioactive molecules loaded aligned core-shell microfibers for tendon tissue engineering

Development of a controlled delivery ultrafine fibrous system with two bioactive molecules is required to stimulate tendon healing in different phase. In this study, we used emulsion stable jet electrospinning to fabricate aligned poly(L-lactic acid) (PLLA) based ultrafine fibers with two small bioactive molecules of L-Arginine (Arg) and low molecular weight hyaluronic acid (HA). The results demonstrated that the aligned Arg/HA/PLLA microfibrous scaffold showed core-shell structure and allowed sequential release of Arg and HA due to their different electric charge. The scaffold also showed enhanced hydrophilicity, cell migration, spread and proliferation. Using an Achilles tendon repair model in rats, we demonstrated that this novel fibrous scaffold can prevent adhesion and promote tendon regeneration. Additionally, two p53 and ER-α-mediated signalling pathways were described as the probable main path of synergistic effects of the novel scaffold on tendon generation. Thus, this study may provide an important strategy for developing biofunctional and biomimetic tendon scaffolds.

Calcium Phosphate Treatment Enhances Osteogenic Differentiation of Porcine Adipose-Derived Stem Cells on Fibrin Scaffolds

This study was designed to develop a fibrin scaffold for optimum in vitro osteogenic differentiation of porcine ASCs. Fibrin scaffolds physically and chemically modified to be stiffer or have higher concentrations of calcium and phosphate ions were hypothesized to enhance osteogenic differentiation compared to control fibrin scaffolds. Treatments during coagulation resulted in six scaffold types for comparison: whole blood controls, red blood cell lysis buffer, calcium chloride, calcium hydrogen phosphate, vacuum, and mechanical compression. Based on the results, fibrin supplemented with granules of calcium hydrogen phosphate (CaHPO4) was determined to be the most suitable formulation of those examined. Using calcium phosphate resulted in a fibrin scaffold that coagulated faster (p = 0.022), had a rougher surface, higher stiffness, and desirable properties for practical use during surgical operations and scaffolds used in bone tissue engineering. Further, osteogenic differentiation was enhanced on scaffolds treated with calcium phosphate. In addition, fibrin scaffolds treated with RBC lysis buffer were also stiffer than untreated controls. These results are partly explained by ASC attachment and fibrin polymerization during coagulation.

The Reliability of PCL/Anti-VEGF Electrospun Scaffolds to Support Limbal Stem Cells for Corneal Repair.

Since only few reported studies propose anti-vascular endothelial growth factor (anti-VEGF) delivery through electrospun scaffolds, this study greatly contributes to the potential prevention of patient's vision loss, as it explores electrospun polycaprolactone (PCL) coated with anti-VEGF for the blockage of abnormal cornea vascularization. In terms of physicochemical properties, the biological component increased the PCL scaffold fiber diameter (by ~24%) and pore area (by ~82%), while ut slightly reduced its total porosity as the anti-VEGF solution filled the voids of the microfibrous structure. The addition of the anti-VEGF increased the scaffold stiffness almost three-fold at both strains of 5 and 10%, as well as its biodegradation rate (~36% after 60 days) with a sustained release profile after Day 4 of phosphate buffered saline incubation. In terms of scaffold application function, the PCL/Anti-VEGF scaffold proved to be more favorable for the adhesion of cultured limbal stem cells (LSCs); this was confirmed by the SEM images, where the cells showed flat and elongated conformations. Further support of the LSC growth and proliferation was confirmed by the identified p63 and CK3 markers after cell staining. These results demonstrate the advantageous effect of the surface-adsorbed anti-VEGF to stop vision loss and help damaged corneal tissue repair.

Preparation and evaluation of a polycaprolactone/chitosan/propolis fibrous nanocomposite scaffold as a tissue engineering skin substitute.

Recently, the application of nanofibrous mats for dressing skin wounds has received great attention. In this study, we aimed to fabricate and characterize an electrospun nanofibrous mat containing polycaprolactone (PCL), chitosan (CTS), and propolis for use as a tissue-engineered skin substitute. Raw propolis was extracted, and its phenolic and flavonoid contents were measured. The physiochemical and biological properties of the fabricated mats, including PCL, PCL/CTS, and PCL/CTS/Propolis were evaluated by scanning electron microscopy (SEM), atomic force microscopy (AFM), mechanical analysis, swelling and degradation behaviors, contact angle measurement, cell attachment, DAPI staining, and MTT assay. On the other hand, the drug release pattern of propolis from the PCL/CTS/Propolis scaffold was determined. A deep second-degree burn wound model was induced in rats to investigate wound healing using macroscopical and histopathological evaluations. The results revealed that the propolis extract contained high amounts of phenolic and flavonoid compounds. The fabricated scaffold had suitable physicochemical and mechanical properties. Uniform, bead-free, and well-branched fibers were observed in SEM images of mats. AFM analysis indicated that the addition of CTS and propolis to PCL elevated the surface roughness. MTT results revealed that the electrospun PCL/CTS/Propolis mat was biocompatible. The presence of fibroblast cells on the PCL/CTS/Propolis mats was confirmed by DAPI staining and SEM images. Also, propolis was sustainably released from the PCL/CTS/Propolis mat. The animal study revealed that addition of propolis significantly improved wound healing. The nanofibrous PCL/CTS/Propolis mat can be applied as a tissue-engineered skin substitute for healing cutaneous wounds, such as burn wounds.