Polycaprolactone Scaffolds Research Articles

Spray nebulization enables polycaprolactone nanofiber production in a manner suitable for generation of scaffolds or direct deposition of nanofibers onto cells

Spray nebulization is an elegant, but relatively unstudied, technique for scaffold production. Herein we fabricated mesh scaffolds of polycaprolactone (PCL) nanofibers via spray nebulization of 8% PCL in dichloromethane (DCM) using a 55.2 kPa compressed air stream and 17 ml h−1 polymer solution flow rate. Using a refined protocol, we tested the hypothesis that spray nebulization would simultaneously generate nanofibers and eliminate solvent, yielding a benign environment at the point of fiber deposition that enabled the direct deposition of nanofibers onto cell monolayers. Nanofibers were collected onto a rotating plate 20 cm from the spray nozzle, but could be collected onto any static or moving surface. Scaffolds exhibited a mean nanofiber diameter of 910 ± 190 nm, ultimate tensile strength of 2.1 ± 0.3 MPa, elastic modulus of 3.3 ± 0.4 MPa, and failure strain of 62 ± 6%. In vitro, scaffolds supported growth of human keratinocyte cell epithelial-like layers, consistent with potential utility as a dermal scaffold. Fourier-transform infrared spectroscopy demonstrated that DCM had vaporized and was undetectable in scaffolds immediately following production. Exploiting the rapid elimination of DCM during fiber production, we demonstrated that nanofibers could be directly deposited on to cell monolayers, without compromising cell viability. This is the first description of spray nebulization generating nanofibers using PCL in DCM. Using this method, it is possible to rapidly produce nanofiber scaffolds, without need for high temperatures or voltages, yielding a method that could potentially be used to deposit nanofibers onto cell cultures or wound sites.

Fabrication and Properties of a Hybrid Biocompatible Nanofiber Mesh Constituted of Polycaprolactone and Self-Assembly Peptide

Conventional therapeutic methods for organ and tissue deficiencies include surgical reconstruction, organ transplantation, medical devices treatment, synthetic prosthesis and so on, of which the application is limited when donors exhibit a low availability and impaired organs and tissues cannot well perform their functions. Tissue Engineering (TE) can harmonize with regional organs or tissues, ensure optimal degradation time for novel structure rebirth, facilitate cell adhesiveness, contribute to cell procreation and differentiation in tissue scaffolds, etc., making it an alternative option for treating pathological obstacles. Artificial polymers such as polycaprolactone (PCL) and nature materials such as peptides are adopted for the fabrication of nanofiber scaffolds. The study first engineered porous PCL scaffolds for examining the fiber morphology and the diameter alternations considering the change of single variable condition of the solution concentration, voltage and electrode distance, etc., thereby finding the basic conditions for producing nanofiber scaffolds with good formation. With the increase in solution concentration, the more obvious molecule entanglement can limit the jet stretching, thereby enlarging the fiber diameters. Voltage negatively impacts the fiber diameters, and elevated voltage can strengthen the electric intensity, thereby leading to a complete stretching of cone jets and making fiber diameters thinner. Besides, increased electrode distance is followed by expanded flight distance and decreased electrode intensity (constant voltage), as a result, fibers become narrower. Nanofiber substance exhibits the optimal performance under the condition of solution concentration: 6%, voltage: 50kV, and electrode distance: 150mm. Subsequently, nanofiber scaffolds were fabricated based on the respective preparation of PCL/P11-4 and PCL/P11-8 polymer solutions. Both P11-4 and P11-8 presented uneven distribution in PCL scaffolds, which involved various PCL nanofiber substances with abundant peptides. PCL nanofiber scaffolds saw the breakage of P11-4 and P11-8 fibers.

Electrical Stimulation Therapy and HA/TCP Composite Scaffolds Modulate the Wnt Pathways in Bone Regeneration of Critical-Sized Defects.

Critical bone defects are the most difficult challenges in the area of tissue repair. Polycaprolactone (PCL) scaffolds, associated with hydroxyapatite (HA) and tricalcium phosphate (TCP), are reported to have an enhanced bioactivity. Moreover, the use of electrical stimulation (ES) has overcome the lack of bioelectricity at the bone defect site and compensated the endogenous electrical signals. Such treatments could modulate cells and tissue signaling pathways. However, there is no study investigating the effects of ES and bioceramic composite scaffolds on bone tissue formation, particularly in the view of cell signaling pathway. This study aims to investigate the application of HA/TCP composite scaffolds and ES and their effects on the Wingless-related integration site (Wnt) pathway in critical bone repair. Critical bone defects (25 mm2) were performed in rats, which were divided into four groups: PCL, PCL + ES, HA/TCP and HA/TCP + ES. The scaffolds were grafted at the defect site and applied with the ES application twice a week using 10 µA of current for 5 min. Bone samples were collected for histomorphometry, immunohistochemistry and molecular analysis. At the Wnt canonical pathway, HA/TCP and HA/TCP + ES groups showed higher Wnt1 and β-catenin gene expression levels, especially HA/TCP. Moreover, HA/TCP + ES presented higher Runx2, Osterix and Bmp-2 levels. At the Wnt non-canonical pathway, HA/TCP group showed higher voltage-gated calcium channel (Vgcc), calmodulin-dependent protein kinase II, and Wnt5a genes expression, while HA/TCP + ES presented higher protein expression of VGCC and calmodulin (CaM) at the same period. The decrease in sclerostin and osteopontin genes expressions and the lower bone sialoprotein II in the HA/TCP + ES group may be related to the early bone remodeling. This study shows that the use of ES modulated the Wnt pathways and accelerated the osteogenesis with improved tissue maturation.

Peptide derived from stromal cell-derived factor 1δ enhances the in vitro expression of osteogenic proteins via bone marrow stromal cell differentiation and promotes bone formation in in vivo models.

Mesenchymal stem cells (MSCs) rely on chemokines and chemokine receptors to execute their biological and physiological functions. Stromal cell-derived factor-1 (SDF-1) is upregulated in injury sites, where it acts as a chemotactic agent, attracting CXCR4-expressing MSCs, which play a pivotal role in the healing and regeneration of tissue throughout the body. Furthermore, SDF-1 expression has been observed in regions experiencing inflammation-induced bone destruction and fracture sites. In this study, we identified a novel peptide called bone-forming peptide-5 (BFP-5), derived from SDF-1δ, which can promote the osteogenesis of MSCs as well as bone formation and healing. Multipotent bone marrow stromal cells treated with BFP-5 showed enhanced alizarin red S staining and higher alkaline phosphatase (ALP) activity. Moreover, ALP and osterix proteins were more abundantly expressed when cells were treated with BFP-5 than SDF-1α. Histology and microcomputed tomography data at 12 weeks demonstrated that both rabbit and goat models transplanted with polycaprolactone (PCL) scaffolds coated with BFP-5 showed significantly greater bone formation than animals transplanted with PCL scaffolds alone. These findings suggest that BFP-5 could be useful in the development of related therapies for conditions associated with bones.

85 - Polycaprolactone scaffolds as a biomaterial for cementoblast delivery: An in vitro study

85 - Polycaprolactone scaffolds as a biomaterial for cementoblast delivery: An in vitro study

Structurally optimized electrospun scaffold for biomaterial-controlled synergistic enhancement of defective bone healing

Bone repair processes are tightly affected by fiber topographies of scaffolds and can be promoted by coupling with chemotactic and/or angiogenic molecules. Here, we developed polycaprolactone (PCL) and collagen-based fibrous scaffolds expressing various architectures via a modified electrospinning set up. We conjugated the as-spun scaffolds with caffeic acid (CA) and/or a cartilage oligomeric matrix protein of angiopoietin 1 (COMP-Ang1). The CA-coupled PCL/collagen scaffold (PCL/col/CA) exhibited greater treatment efficacies for biomimetic and cellular mineralization, expression of osteogenic and chemotactic molecules, and cell migration than did the PCL/col treatment alone. Among the PCL/col/CA scaffolds, the radially symmetric grid-patterned scaffold (rG-PCL/col/CA) showed the greatest bioactivities. The linking of the rG-PCL/col/CA with COMP-Ang1 increased the expression of vascular endothelial growth factor by cells. The COMP-Ang1-linked rG-PCL/col/CA formed more new blood vessels and expressed more chemotactic molecules in a rat model of femoral defects than did the scaffold alone. Compared with PCL/col/CA scaffolds, the COMP-Ang1-coupled rG-PCL/col/CA scaffold stimulated faster and greater healing of femoral defects. Collectively, this study demonstrates that the coupling of a radially grid-patterned fibrous scaffold with CA and COMP-Ang1 greatly enhances scaffold-mediated bone healing via synergistic improvements in vascularization, cell migration, and formation and maturation of new bones in defected regions.

Cell Behavior Changes and Enzymatic Biodegradation of Hybrid Electrospun Poly(3-hydroxybutyrate)-Based Scaffolds with an Enhanced Piezoresponse after the Addition of Reduced Graphene Oxide.

This is the first comprehensive study of the impact of biodegradation on the structure, surface potential, mechanical and piezoelectric properties of poly(3-hydroxybutyrate) (PHB) scaffolds supplemented with reduced graphene oxide (rGO) as well as cell behavior under static and dynamic mechanical conditions. There is no effect of the rGO addition up to 1.0 wt% on the rate of enzymatic biodegradation of PHB scaffolds for 30 d. The biodegradation of scaffolds leads to the depolymerization of the amorphous phase, resulting in an increase in the degree of crystallinity. Because of more regular dipole order in the crystalline phase, surface potential of all fibers increases after the biodegradation, with a maximum (361 ± 5mV) after the addition of 1 wt% rGO into PHB as compared to pristine PHB fibers. By contrast, PHB-0.7rGO fibers manifest the strongest effective vertical (0.59 ± 0.03 pm V-1 ) and lateral (1.06 ± 0.02 pm V-1 ) piezoresponse owing to a greater presence of electroactive β-phase. In vitro assays involving primary human fibroblasts reveal equal biocompatibility and faster cell proliferation on PHB-0.7rGO scaffolds compared to pure PHB and nonpiezoelectric polycaprolactone scaffolds. Thus, the developed biodegradable PHB-rGO scaffolds with enhanced piezoresponse are promising for tissue-engineering applications.

Advances in additive manufacturing of polycaprolactone based scaffolds for bone regeneration.

Critical sized bone defects are difficult to manage and currently available clinical/surgical strategies for treatment are not completely successful. Polycaprolactone (PCL) which is a biodegradable and biocompatible thermoplastic can be 3D printed using medical images into patient specific bone implants. The excellent mechanical properties and low immunogenicity of PCL makes it an ideal biomaterial candidate for 3D printing of bone implants. Though PCL suffers from the limitation of being bio-inert. Here we describe the use of PCL as a biomaterial for 3D printing for bone regeneration, and advances made in the field. The specific focus is on the different 3D printing techniques used for this purpose and various modification that can enhance bone regeneration following the development pathways. We further describe the effect of various scaffold characteristics on bone regeneration both in vitro and the translational assessment of these 3D printed PCL scaffolds in animal studies. The generated knowledge will help understand cell-material interactions of 3D printed PCL scaffolds, to further improve scaffold chemistry and design that can replicate bone developmental processes and can be translated clinically.

Hydrogel coating based on dopamine-modified hyaluronic acid and gelatin with spatiotemporal drug release capacity for quick endothelialization and long-term anticoagulation

Due to the vital roles of vascular intima in preventing thrombus generation and maintaining vascular patency, methods to promote quick endothelialization on vascular grafts have drawn much attention. In this study, we novelly applied a double-layered hydrogel coating with spatiotemporal drug release capacity on a polycaprolactone (PCL) fibrous scaffold. The composite coating consisted of an inner dopamine-modified hyaluronic acid (HA) hydrogel and an outer gelatin hydrogel, which were generated via different crosslinking methods. Especially, heparin and chondroitin sulfate were introduced to the HA and gelatin hydrogels during the processing, thus endowing the vascular scaffold spatiotemporal drug release behavior. The composite coating developed surface hydrophilicity and mechanical properties of the PCL scaffold meanwhile stimulating the proliferation and angiogenesis behaviors of endothelial cells. Long-term anticoagulation property of the modified scaffold was also demonstrated in vitro. This investigation provides a universal strategy for quick endothelialization and long-term anticoagulation promotion of vascular grafts, which may be potentially used in treating cardiovascular diseases.

Polycaprolactone-based scaffolds for guided tissue regeneration in periodontal therapy: A systematic review.

Polycaprolactone (PCL) is a highly recognized synthetic polymer for its biocompatibility, ease of fabrication and mechanical strength in bone tissue engineering. Its applications have extended broadly, including regeneration of oral and maxillofacial lost tissues. Its usefulness has brought attention of researchers to regenerate periodontal lost tissues, including alveolar bone, periodontal ligament and cementum. The aim of this systematic review was to obtain an updated analysis of the contribution of PCL-based scaffolds in the alveolar bone regeneration process. This review adheres to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews. A computerized search of the PubMed, EBSCO, Scielo and Web of Science databases was performed, restricting literature search to published studies in English or Spanish between January 2002 and March 2023. Database search returned 248 studies which were screened based on title, author names and publication dates. Data from 17 studies were reviewed and tabulated. All studies combined PCL with other biomaterials (such as Alginate, hydroxyapatite, bioactive glass, poly (lactic-co-glycolic acid)), growth factors (BMP-2, rhCEMP1), and/or mesenchymal stromal cells (adipose-derived, bone marrow, periodontal ligament or gingiva mesenchymal stromal cells). PCL scaffolds showed higher cell viability and osteoinductive potential when combined with bioactive agents. Complementary, its degradation rates were affected by the addition or exposure to specific substances, such as: Dopamine, Cerium Oxide, PLGA and hydrogen peroxide. PCL is an effective biomaterial for alveolar bone regeneration in periodontally affected teeth. It could be part of a new generation of biomaterials with improved regenerative potential.

Activated carbon nanofiber nanoparticles incorporated electrospun polycaprolactone scaffolds to promote fibroblast behaviors for application to skin tissue engineering

The most widely used one-dimensional (1D) carbonaceous nanomaterials in tissue engineering are carbon nanotubes, either single or multiwalled. Other forms of 1D nanomaterials, such as carbon nanowires and carbon nanofibers, have been less explored for biomedical applications. Herein, we synthesized 1D-activated carbon nanofiber nanoparticles (ACNF NPs) from the polyacrylonitrile electrospun nanofibers by continuous processes like stabilization, alkali treatment, calcination, and grinding. Two different sets of ACNF NPs-containing electrospun polycaprolactone (PCL) nanofiber mats, viz. surface-modified NP-deposited mats (ACNF@PCL) and NP-incorporated mats (ACNF-PCL), were prepared to examine their potential as skin tissue engineering scaffolds. Raman spectra demonstrated that ACNF NPs exhibited graphitization degree with an ID/IG ratio of 1.05. Scanning electron microscopy (SEM) observations showed that ACNF NPs are sized 280 ± 100 nm by diameter and 565–3322 nm by length. The NPs concentrated above 30 μg/mL were found to exhibit toxicity with < 70% viability of NIH3T3 fibroblasts on 48 h. The ACNF-PCL nanofiber mats displayed better cell proliferation profile showing significant changes compared to PCL and ACNF@PCL mats on days 1, 3, and 5. Hence, we concluded that ACNF-PCL mats with less concentration of ACNF NPs have more potential to support cellular growth, ensuring its possible impact on skin tissue regeneration.Graphical Abstract

Successful Islet Transplantation Into a Subcutaneous Polycaprolactone Scaffold in Mice and Pigs.

In this study, we developed and compared scaffolds made of poly(D,L,-lactide-co-ε-caprolactone) (PDLLCL) and polycaprolactone (PCL). Efficacy was first tested in mice' and then, as a proof of principle for application in a large animal model, the scaffolds were tested in pigs, as their skin structure is similar to that of humans. In mice, islet transplantation in a PCL scaffold expedited return to normoglycemia in comparison to PDLLCL (7.7 ± 3.7 versus 16.8 ± 6.5 d), but it took longer than the kidney capsule control group. PCL also supported porcine functional islet survival in vitro. Subcutaneous implantation of PDLLCL and PCL scaffolds in pigs revealed that PCL scaffolds were more stable and was associated with less infiltration by immune cells than PDLLCL scaffolds. Prevascularized PCL scaffolds were therefore used to demonstrate the functional survival of allogenic islets under the skin of pigs. To conclude, a novel PCL scaffold shows efficacy as a readily accessible and replaceable, subcutaneous transplantation site for islets in mice and demonstrated islet survival after a month in pigs.

Hybrid 3D Printed and Electrospun Multi-Scale Hierarchical Polycaprolactone Scaffolds to Induce Bone Differentiation.

Complex scaffolds composed of micro- and nano-structures are a key target in tissue engineering and the combination of sequential 3D printing and electrospinning enables the fabrication of these multi-scale structures. In this work, dual 3D printed and electrospun polycaprolactone (PCL) scaffolds with multiple mesh layers were successfully prepared. The scaffold macro- and micro-porosity were assessed by optical and scanning electron microscopy, showing that electrospun fibers formed aligned meshes within the pores of the scaffold. Consequently, the hydrophilicity of the scaffold increased with time, enhancing cell adhesion and growth. Additionally, compression tests in back and forth cycles demonstrated a good shape recovery behavior of the scaffolds. Biological results indicated that hybrid PCL scaffolds are biocompatible and enable a correct cell culture over time. Moreover, MC3T3-E1 preosteoblast culture on the scaffolds promoted the mineralization, increased the alkaline phosphatase (ALP) activity and upregulated the expression of early and late osteogenic markers, namely ALP and osteopontin (OPN), respectively. These results demonstrate that the sequential combination of 3D printing and electrospinning provides a facile method of incorporating fibers within a 3D printed scaffold, becoming a promising approach towards multi-scale hierarchical scaffolds capable of guiding the osteogenic differentiation.

High-resolution 3D printing of angle-ply annulus fibrosus scaffolds for intervertebral disc regeneration

Intervertebral disc (IVD) degeneration is one of the leading causes of disability, and current therapies are mainly unsatisfactory. The key pathological feature during IVD degeneration is the dysfunction of annulus fibrosus (AF). Although tissue-engineered AF has shown great promise for IVD regeneration, the design and fabrication of biomimetic AF scaffold remains a challenge due to the complexity of its structure. Nowadays, 3D printing technology has drawn great attention due to its customizable processes and ability to produce complex tissue architecture. However, few existing 3D printing methods can accurately replicate the fine angle-ply architecture of native AF, which is one of the most critical steps for IVD regeneration, due to the limited printing resolution. In this study, we aimed to fabricate high-resolution polycaprolactone (PCL) scaffolds using a newly developed electrohydrodynamic 3D printing technique. The structural advantages of such scaffolds were verified by finite element analysis (FEA). The PCL scaffolds were further assembled into AF construct to replicate the angle-ply architecture of AF. The optimal assembling method was confirmed by FEA and mechanical tests. The in vitro experiments showed that the 3D printed AF scaffolds presented favorable biocompatibility and supported the adhesion and growth of AF cells. The in vivo performance of tissue-engineered IVDs (TE-IVDs), which consisted of 3D printed AF scaffold and GelMA hydrogel that simulated nucleus pulposus (NP), were evaluated using a rat total disc replacement model. We found that the implantation of TE-IVDs helped maintain the disc height, reduced the loss of NP water content, and partially restored the biomechanical function of IVD. In addition, the TE-IVDs achieved well integration with adjacent tissues and promoted new tissue formation. In summary, being able to accurately simulate the structural characteristics of native AF, the 3D printed angle-ply AF scaffolds hold potential for future applications in IVD regeneration.

A novel method for investigation of the impact of sterilization by gamma radiation on polycaprolactone scaffold

Structural properties of materials irradiated with gamma-rays, such as mechanical and physical properties, may be modified or reduced depending on the displacement damages. Apart from increasing or decreasing that property, damage may be desirable or not. This study investigates the effects of sterilization by gamma radiation on polycaprolactone (PCL) scaffolds. Using a code-based simulation method, MCNPX provides information on primary knock-on atoms, or PKAs, that cause damage. A program has been developed called GAMMATRACK to access PKA information. These PKA data can be used as input for the SRIM code to analyze gamma damage systematically. The rate of damage caused by gamma radiation is calculated on the PCL target. The theoretical calculation method also has been used to confirm the results of the Monte Carlo method (MCNPX + SRIM code). Due to the low-energy PKAs and the thin target possibility of the displacement cascade can be ignored. It is realized that all displacements are due to single vacancies. The total number of hydrogens, carbons, and oxygen PKAs were obtained. It was found that the number of carbons PKA is more than the others, which causes three-dimensional polymer networks to be created. In the experimental analysis, it is necessary to know the appropriate depth of the sample for damage investigation. GAMMATRACK gives the gamma displacement damage graph along the length of the PCL. It shows a uniform distribution of displacement damage. The damage rate for the PCL target is calculated, and the results between the theoretical calculations and the Monte Carlo method (MCNPX + SRIM code) differ by about 17%.

A novel approach to bio-mineralization of electrospun PCL scaffolds by protein and hydroxyapatite nanoparticles; molecular dynamics simulation and in-vitro evaluation

The nano-fibrous polycaprolactone (PCL) scaffolds are one of the promising materials for bone tissue engineering. However, the role of protein in the bio-mineralization of PCL fibers is not clear. This study aims to find how a protein (e.g. bovine serum albumin (BSA)) is attached to the hydroxyapatite (HA) nanoparticles (NPs) loaded on the PCL fiber, and it affected the bio-mineralization of a hybrid scaffold. The molecular dynamic (MD) simulation was utilized to explore the protein and HA attachment. The results of MD simulation indicated that the a(b)-planes of HA crystal and glutamic acid (Glu) from BSA molecule have critical roles in attachment together. In the following, the electrospinning method was applied to synthesize the pristine and hybrid PCL scaffolds to evaluate the MD results. The scanning electron microscopy (SEM) images showed that BSA could be successfully attached to the HA NPs, and coiled around the PCL-HA junction confirming the MD simulation. To evaluate the bio-mineralization, the in-vitro immersion test in the simulation body fluid (SBF) solution and the cytocompatibility of scaffolds by the MG63 osteosarcoma cells were studied. The results indicated better osteoconduction and bone regeneration for the hybrid PCL- BSA-HA scaffold because of the synergic effects of HA NPs and BSA protein.

Parametric Numerical Modeling and Fabrication of PCL Scaffolds for Bone Tissue Engineering Applications

Bone tissue engineering (BTE) is an interdisciplinary discipline that focuses on bone structure–function relationships for improving the replacement and/or regeneration of bone tissues. Thereby, the architecture and load-bearing capacity of embedded scaffolds play an important role in the generation of artificial tissues. The aim of this study was to develop a parametric numerical model and the accompanying fabrication of polycaprolactone (PCL) scaffolds for BTE applications. Therefore, we manufactured layered PCL-based constructs using three-dimensional (3D) printing. The material properties of PCL and constructs were determined by mechanical testing, and numerical models based on Beam188 Timoshenko elements were developed in the software environment ANSYS. PCL constructs were coated with collagen and seeded with osteoblasts, mesenchymal stem cells (MSCs), MLO-Y4 and MG63 cell types. We demonstrated the successful production of PCL constructs with 3D interconnected pores suitable for BTE applications. Furthermore, we provided for the first time geometrical parametric numerical models that determined the mechanical behavior of layered PCL scaffolds consisting of interconnected compartments for strains up to 3%. The parametric structures of the model allowed us to flexibly study new geometries in silico, which demonstrated its role as an important tool for supporting the fabrication of customized PCL constructs in planning and performing suitable mechanical characterizations for BTE applications.

Assessment of 3D-Printed Polycaprolactone, Hydroxyapatite Nanoparticles and Diacrylate Poly(ethylene glycol) Scaffolds for Bone Regeneration.

Notwithstanding the advances achieved in the last decades in the field of synthetic bone substitutes, the development of biodegradable 3D-printed scaffolds with ideal mechanical and biological properties remains an unattained challenge. In the present work, a new approach to produce synthetic bone grafts that mimic complex bone structure is explored. For the first time, three scaffolds of various composition, namely polycaprolactone (PCL), PCL/hydroxyapatite nanoparticles (HANp) and PCL/HANp/diacrylate poly(ethylene glycol) (PEGDA), were manufactured by extrusion. Following the production and characterisation of the scaffolds, an in vitro evaluation was carried out using human dental pulp stem/stromal cells (hDPSCs). Through the findings, it was possible to conclude that, in all groups, the scaffolds were successfully produced presenting networks of interconnected channels, adequate porosity for migration and proliferation of osteoblasts (approximately 50%). Furthermore, according to the in vitro analysis, all groups were considered non-cytotoxic in contact with the cells. Nevertheless, the group with PEGDA revealed hydrophilic properties (15.15° ± 4.06) and adequate mechanical performance (10.41 MPa ± 0.934) and demonstrated significantly higher cell viability than the other groups analysed. The scaffolds with PEGDA suggested an increase in cell adhesion and proliferation, thus are more appropriate for bone regeneration. To conclude, findings in this study demonstrated that PCL, HANp and PEGDA scaffolds may have promising effects on bone regeneration and might open new insights for 3D tissue substitutes.

Thermal stability and antibacterial activity of Er2O3, and Co3O4 scattered in polycaprolactone

The development of a biocompatible wound dressing with good antibacterial and fasting for healing skin wounds is still a challenge. Through the film casting, a polycaprolactone (PCL) scaffold is manufactured with different ratios of metal oxides such as Erbium oxide (Er2O3) and Cobalt oxide (Co3O4). The fabricated films were examined using XRD, SEM, FTIR, and XPS. The study of surface morphology exhibits diameters of pores in the range of 1–7 µm. The contact angle tested with a drop of water and showed that it is in decreased from 55.67˚ for pure PCL then lowered to 47.85˚ for Er2O3@PCL and slightly decreased to 41.195˚ for Co3O4@PCL and a significant decrease occurred to 34.435˚ for Er2O3/Co3O4@PCL and then it slightly increased to 38.02˚ for Er2O3/Co3O4/GO@PCL. In addition, the TGA started from room temperature up to 200 °C by a weight loss of around 3 %. The cell viability is examined for Er2O3/Co3O4/GO@PCL and it showed that the IC50 at 4000 µg/ml and with lowering the concentration, the viable cells tend to increase. On the other hand, an antibacterial test against E. coli and S. aureus showed high antibacterial activity in Er2O3/Co3O4/GO@PCL. The wound bandages were developed using loaded materials which represent good biocompatibility, biodegradability, and high antibacterial behavior that inhibit bacterial growth on the surface of the wound which might accelerate the wound healing period. Moreover, it has been approved that, the surface porosity might enhance the mutual transfer of gases between the wound and the outer environment.

Fabrication and Characterization of Decellularized Periodontal Ligament Cell Sheet Constructs.

Decellularized tissue engineered constructs have the potential to promote regeneration by providing a biomimetic extracellular matrix that directs tissue specific regeneration when implanted in situ. Recently, the use of cell sheets has shown promising results in promoting periodontal regeneration. Here, we describe the fabrication of decellularized periodontal cell sheets with intact extracellular matrix structural and biological properties. Melt electro-spun polycaprolactone (PCL) scaffolds are used as a carrier for the inherently fragile cell sheets, in order to provide support during the processes of decellularization. An optimized decellularization method is outlined using perfusion with a combination of NH4OH and Triton X-100 together with a DNase treatment step for DNA removal. The maintenance of extracellular matrix structural and biological integrity is important, and here, we describe the assessment of these properties using immunostaining for extracellular matrix proteins and ELISA for growth factor quantification.