Blend Scaffolds Research Articles

Freeze-gelled alginate/gelatin scaffolds for wound healing applications: An in vitro, in vivo study.

In this study, fabrication of a three-dimensional porous scaffold was performed using freeze gelation method. Recently, fabrication of scaffolds using polymer blends has become common for many tissue engineering applications due to their unique tunable properties. In this work, we fabricated alginate-gelatin porous hydrogels for wound healing application using a new method based on some modifications to the freeze-gelation method. Alginate and gelatin were mixed in three different ratios and the resulting solutions underwent freeze gelation to obtain 3D porous matrices. We analyzed the samples using different characterization tests. The scanning electron microscopy (SEM) results indicated that the freeze gelation method was successful in obtaining porous morphologies for all the fabricated alginate-gelatin samples as previously was seen in single-polymer fabrication using this method. The alginate to gelatin ratio affected swelling, biodegradation, cell culture and mechanical properties of the matrices. The scaffold with the lowest content of gelatin had the highest swelling ratio while biodegradation and cell proliferation and viability were increased with the gelatin content. Regarding the mechanical properties, as the gelatin content increased, the scaffold became more ductile and showed higher tensile strength. The in-vivo results also showed the biocompatibility of the blend scaffold and its positive role in wound healing process in rats. The low-cost procedure used in this study to fabricate the porous alginate-gelatin scaffolds can be adapted and modified to suit different tissue engineering applications.

Magnesium-containing silk fibroin/polycaprolactone electrospun nanofibrous scaffolds for accelerating bone regeneration

Bone tissue engineering has become one of the most effective methods for treating bone defects. In this study, an electrospun tissue engineering membrane containing magnesium was successfully fabricated by incorporating magnesium oxide (MgO) nanoparticles into silk fibroin and polycaprolactone (SF/PCL)-blend scaffolds. The release kinetics of Mg2+ and the effects of magnesium on scaffold morphology, and cellular behavior were investigated. The obtained Mg-functionalized nanofibrous scaffolds displayed controlled release of Mg2+, satisfactory biocompatibility and osteogenic capability. The in vivo implantation of magnesium-containing electrospun nanofibrous membrane in a rat calvarial defect resulted in the significant enhancement of bone regeneration twelve weeks post-surgery. This work represents a valuable strategy for fabricating functional magnesium-containing electrospun scaffolds that show potential in craniofacial and orthopedic applications.

Tissue transglutaminase_variant 2-transduced mesenchymal stem cells and their chondrogenic potential.

As cartilage is incapable of self-healing upon severe degeneration because of the lack of blood vessels, cartilage tissue engineering is gaining importance in the treatment of cartilage defects. This study was designed to improve cartilage tissue regeneration by expressing tissue transglutaminase variant 2 (TGM2_v2) in mesenchymal stem cells (MSC) derived from bone marrow of rats. For this purpose, rat MSCs transduced with TGM2_v2 were grown and differentiated on three-dimensional polybutylene succinate (PBSu) and poly-l-lactide (PLLA) blend scaffolds. The transduced cells could not only successfully express the short form transglutaminase-2, but also deposited the protein onto the scaffolds. In addition, they could spontaneously produce cartilage-specific proteins without any chondrogenic induction, suggesting that TGM2_v2 expression provided the cells the ability of chondrogenic differentiation. PBSu:PLLA scaffolds loaded with TGM2_v2 expressing MSCs could be used in repair of articular cartilage defects.

Evaluation of the potential of chimeric spidroins/poly(L-lactic-co-ε-caprolactone) (PLCL) nanofibrous scaffolds for tissue engineering.

In this study, a novel type of chimeric spider silk proteins (spidroins) NTW1-4CT was blended with poly(L-lactic-co-ε-caprolactone) (PLCL) to obtain nanofibrous scaffolds via electrospinning. Spidroins are composed of a N-terminal module (NT) from major ampullate spidroins, a C-terminal module (CT) from minor ampullate spidroins and 1-4 repeat modules (W) from aciniform spidroins. Physical characteristics and structures of NTW1-4CT/PLCL (25/75, w/w) blend scaffolds were carried out by scanning electron microscope (SEM), water contact angles measurements, Fourier transform infrared (FTIR) spectroscopy and tensile mechanical tests. Results showed that blending with spidroins decreased diameters of nanofibers and increased porosity and wettability of scaffolds. Additionally, chimeric spidroins undergone a similar structural transition in electrospinning process as with the formation process of native and artificial spider silks from other spidroins. With amounts of W modules increasing, the tensile strength and elongation of blend scaffolds were also increased. Particularly, NTW4CT/PLCL (25/75) scaffolds revealed much higher breaking stress than pure PLCL scaffolds. In vitro experiments, human umbilical vein endothelial cells (HUVEC) cultured on NTW4CT/PLCL (25/75) scaffolds displayed significantly higher activity of proliferation and adhesion than on pure PLCL scaffolds. All results suggested that chimeric spidroins/PLCL, especially NTW4CT/PLCL (25/75) blend nanofibrous scaffolds had promising potential for vascular tissue engineering.

Aligned nanofibers of decellularized muscle extracellular matrix for volumetric muscle loss

Volumetric muscle loss (VML) is a traumatic loss of muscle tissue that results in chronic functional impairment. When injured, skeletal muscle is capable of small-scale repair; however, regenerative capacities are lost with VML due to a critical loss stem cells and extracellular matrix (ECM). Consequences of VML include either long-term disability or delayed amputations of the affected limb. While the prevalence of VML is substantial, currently a successful clinical therapy has not been identified. In a previous study, an electrospun composed of polycaprolactone (PCL) and decellularized-ECM (D-ECM) supported satellite cell-mediated myogenic activity in vitro. In this study, we investigate the extent to which this electrospun scaffold can support functional muscle regeneration in a murine model of VML. Experimental groups included no treatment, pure PCL treated, and PCL:D-ECM (50:50 blend) treated VML defects. The PCL:D-ECM scaffold treated VML muscles supported increased activity of anti-inflammatory M2 macrophages (arginase+ ) at Day 28, compared to other experimental groups. Increased myofiber (MHC+ ) regeneration was observed histologically at both Days 7 and 28 post-trauma in blend scaffold treated group compared to PCL treated and untreated groups. However, improvements in muscle weights and force production were not observed. Future studies would evaluate muscle function at longer time-points post-VML injury to allow sufficient time for reinnervation of regenerated muscle fibers.

Honey Loaded Silk Fibroin 3D Porous Scaffold Facilitates Homeostatic Full-Thickness Wound Healing

Dermal reconstruction in acute and chronic wounds needs highly vascularized dermal tissue engineered skin substitutes which has the potentiality to provide physical cues as well as biological cues for scarless regenerative wound healing. Herein, we have investigated blends of silk fibroin and honey as a wound healing substrate that able to facilitate keratinocyte and fibroblast adhesion, migration and proliferation. Honey-silk fibroin (HSF) three dimensional (3D) scaffolds were fabricated by freeze drying and characterized in detail for their physico-chemical, mechanical, swelling and degradable properties. Interestingly, in vitro studies showed better adhesion, proliferation and homogenous distribution of fibroblasts within blended scaffolds especially with 4% honey concentration (HSF4). Also, its structural composition with interconnected pores in the range of 108-152µm and porosity 82-92% further confirms the superiority over the counterparts and other blended scaffolds. The in vivo cytotoxic studies validated the biocompatibility of HSF4 scaffolds and the infiltration of both types of cells from the neighboring tissue. Fascinatingly, in vivo cutaneous wound healing studies demonstrated the attainment of normal homeostasis with proper re-epithelialization, collagen matrix remodeling having high collagen I expression with minimal scar under HSF4 scaffolds implantation. Taken together, this study suggests the potentiality of incorporation of honey component as a payload which not only augmented the scarless healing also modified the physical properties of scaffold in order to provide the suitable micro-ambience for healing and these material scaffold proved to be a potential dermal substitute for acute as well as chronic wounds.

Biopolymer/Glycopolypeptide-Blended Scaffolds: Synthesis, Characterization and Cellular Interactions.

Three-dimensional (3D) scaffolds formed from natural biopolymers gelatin and chitosan that are chemically modified by galactose have shown improved hepatocyte adhesion, spheroid geometry and functions of the hepatocytes. Galactose specifically binds to the hepatocytes via the asialoglycoprotein receptor (ASGPR) and an increase in galactose density further improves the hepatocyte proliferation and functions. In this work, we aimed to increase the galactose density within the biopolymeric scaffold by physically blending the biopolymers chitosan and gelatin with an amphiphlic β-galactose polypeptide (PPO-GP). PPO-GP, is a di-block copolymer with PPO and β-galactose polypeptide, exhibits lower critical solution temperature and is entrapped within the scaffold through hydrophobic interactions. The uniform distribution of PPO-GP within the scaffold was confirmed by fluorescence microscopy. SEM and mechanical testing of the hybrid scaffolds indicated pore size, inter connectivity and compression modulus similar to the scaffolds made from 100 % biopolymer. The presence of the PPO-GP on the surface of the scaffold was tested monitoring the interaction of an analogous mannose containing PPO-GP scaffold and the mannose binding lectin Con-A. In vitro cell culture experiments with HepG2 cells were performed on GLN-GP and CTS-GP and their cellular response was compared with GLN and CTS scaffolds for a period of seven days. Within three days of culture the Hep G2 cells formed multicellular spheroids on GLN-GP and CTS-GP more efficiently than on the GLN and CTS scaffolds. The multicellular spheroids were also found to infiltrate more in GLN-GP and CTS-GP scaffolds and able to maintain their round morphology as observed by live/dead and SEM imaging.

Electrospun triazole-based chitosan nanofibers as a novel scaffolds for bone tissue repair and regeneration

For the first time, the novel type of guided bone regeneration composite nanofibers were prepared by grafting polycaprolactone (PCL) to chitosan (CS) using the copper (I) - catalyzed azide-alkyne cycloaddition (CuAAC) reaction. For improve the bioactivity of scaffolds the magnesium-doped hydroxyapatite (Mg-HA) was used. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and proton nuclear magnetic resonance (1H NMR) were applied to characterize the prepared scaffolds. The SEM observations show defect-free uniform composite nanofibers with about 419–495 nm diameter. The in vitro cell viability test (MTT assay) show that fabricated scaffolds don’t have any significant cytotoxicity. Also, osteoblast-like MG63 cells cultured on the nanofibers which prepared through CuAAC reaction (CS-g-PCL/Mg-HA) show higher antibacterial activity, mechanical properties, and cell attachment compared to CS/PCL/Mg-HA blend scaffolds. Moreover, the Alkaline phosphatase (ALP) activity and Alizarin red S (ARS) staining showed that the introduction of the triazole ring into the chemical structure of the copolymer enhanced bone mineralization ability of the scaffolds. These results suggested that this novel scaffold provides an interesting option for bone repair and regeneration.

Core-shell insulin-loaded nanofibrous scaffolds for repairing diabetic wounds

Patients with diabetes mellitus have up to a 15% lifetime risk of non-healing and poorly healing wounds. This work develops core-shell nanofibrous bioactive insulin-loaded poly-D-L-lactide-glycolide (PLGA) scaffolds that release insulin in a sustained manner for repairing wounds in diabetic rats. To prepare the biodegradable core-shell nanofibers, PLGA and insulin solutions were fed into two capillary tubes of different sizes that were coaxially electrospun using two independent pumps. The scaffolds sustainably released insulin for four weeks. The hydrophilicity and water-containing capacity of core-shell nanofibrous insulin/PLGA scaffolds significantly exceeded those of blended nanofibrous scaffolds. The nanofibrous core-shell insulin-loaded scaffold reduced the amount of type I collagen in vitro, increased the transforming growth factor-beta content in vivo, and promoted diabetic would repair. The core-shell insulin-loaded nanofibrous scaffolds prolong the release of insulin and promote diabetic wound healing.

Silk fibroin/alumina nanoparticle scaffold using for osteogenic differentiation of rabbit adipose-derived stem cells

In the present study, blended silk fibroin (SF)/alumina nanoparticles were prepared to assess the osteogenic differentiation of rabbit adipose-derived stem cells (rADSCs). The structural and biological behaviours of the nanocomposite were evaluated. Themicro-porous structure of SF/alumina nanocomposite had acceptable mechanical strength, water uptake capacity, and biomineralization capability. Increasing the content of alumina nanoparticles in the structure of SF substrate more than 10% enhanced the physiochemical properties of the bulk SF scaffold without any toxicity effect on the proliferation and attachment of rADSCs. More alkaline phosphates activity and calcium phosphate deposition were also observed in nanocomposite with 10% alumina nanoparticle. Compare with other groups, applying the blended scaffold along with osteogenic medium induced rADSCs to express higher osteogenic markers like collagen type I, osteopontin, RUNX2, and osteocalcin. Taken together, SF/alumina nanocomposite serves as good substrates for proliferation and osteogenic differentiation of ADSCs applicable for bone tissue engineering.

Osteogenic potential of human dental pulp stem cells cultured onto poly-ε-caprolactone/poly (rotaxane) scaffolds

BackgroundBioengineering aims to develop innovative scaffolds to improve cellular activities for tissue regeneration. ObjectivesTo evaluate the biological behavior of human dental pulp stem cells (hDPSCs) seeded onto an experimental polymeric-based scaffold comprising poly-ε-caprolactone/poly (rotaxane). Material and methodsAdhesion, viability, and proliferation as well as alkaline phosphatase (ALP) activity, mineralized nodule formation (alizarin red assay), and expression of genes related to osteogenic differentiation, including ALP, type 1 collagen alpha 1 (COL1A1), Runt-related transcription factor (Runx-2), and osteocalcin (BGLAP/OCN), were evaluated in hDPSCs seeded onto polymeric scaffolds. ResultshDPSCs expressed typical levels of mesenchymal stem cell surface markers. Cell growth increased upon cultivation on polymeric blend scaffold and the cells gained osteoblast-like appearance. Fourteen days after seeding hDPSCs on the scaffolds, irrespective to the culture medium used (clonogenic or mineralization medium), the cells presented ALP activity higher than that of control cells grown in clonogenic medium. The cells cultivated in mineralization medium on the scaffold showed significantly higher expression of all genes than the control cells, except for BGLAP gene expression. At 21 days, the group cultivated on the scaffold and mineralization medium showed maximum level of mineralization. SignificancePoly-ε-caprolactone/poly (rotaxane) blend is noncytotoxic to hDPSCs and improved genomic and functional osteogenic differentiation. Thus, poly-ε-caprolactone/poly (rotaxane) blend may serve as a promising bioactive biomaterial for bone tissue bioengineering.

Blend scaffolds with polyaspartamide/polyester structure fabricated via TIPS and their RGDC functionalization to promote osteoblast adhesion and proliferation

Target of this work was to prepare a RGDC functionalized hybrid biomaterial via TIPS technique to achieve a more efficient control of osteoblast adhesion and diffusion on the three-dimensional (3D) scaffolds. Starting from a crystalline poly(l-lactic acid) (PLLA) and an amorphous α,β-poly(N-2-hydroxyethyl) (2-aminoethylcarbamate)-d,l-aspartamide-graft-polylactic acid (PHEA-EDA-g-PLA) copolymer, blend scaffolds were characterized by an appropriate porosity and pore interconnection. The PHEA-EDA-PLA interpenetration with PLLA improved hydrolytic susceptibility of hybrid scaffolds. The presence of free amino groups on scaffolds allowed to tether the cyclic RGD peptide (RGDC) via Michael addition using the maleimide chemistry. Cell culture test carried out on preosteoblastic cells MC3T3-E1 incubated with scaffolds, has evidenced cell adhesion and proliferation. Furthermore, the presence of distributed bone matrix on all scaffolds was evaluated after 70 days compared to PLLA only samples.

Extrusion-based 3D printing of photo-crosslinkable gelatin and κ-carrageenan hydrogel blends for adipose tissue regeneration

Current soft tissue repair techniques for women with breast cancer remain associated with several drawbacks including surgical complications and a high resorption rate for lipofilling techniques. Hence, the need to develop improved adipose tissue reconstruction strategies. Additive manufacturing can be a promising tool towards the development of patient-specific scaffolds which are able to support adipose tissue engineering. In the present work, scaffolds composed of both methacrylamide-modified gelatin (Gel-MA) and methacrylated κ-carrageenan (Car-MA), i.e. hydrogel blends, were developed using extrusion-based 3D printing in order to establish a close resemblance to the native extracellular matrix. The hydrogel blends were benchmarked to scaffolds constituting of only Gel-MA. Our results indicate that both types of scaffolds remain stable over time (21 days), are able to absorb large amounts of water and exhibit mechanical properties comparable to those of native breast tissue (2 kPa). Furthermore, a similar cell viability (> 90%) and proliferation rate after 14 days was obtained for adipose tissue-derived stem cells (ASCs) upon seeding onto both types of scaffolds. Additionally, the ASCs were able to differentiate into the adipogenic lineage on the hydrogel blend scaffolds, although their differentiation potential was lower compared to that of ASCs seeded onto the Gel-MA scaffolds.

Fabrication of porous scaffold by ternary combination of chitosan, gelatin, and calcium phosphate for tissue engineering

Recently, 3D porous scaffolds using naturally derived polymers, i.e. chitosan (CHN), gelatin (GLN), and their blends have attracted attentions for tissue engineering applications. Research on the use of polymers and ceramic composites has been performed to improve biocompatibility of tissue scaffolds. However, calcium phosphate (CaP) coating on CHN/GLN blend scaffolds has not been well studied. In this study, we fabricated CHN/GLN films and scaffolds at various CHN/GLN blending ratios (100/0, 75:25, 50/50, 25/75, and 0/100) and established optimal CaP coating method on CHN/GLN blends. Increase in GLN content promoted both surface hydrophilicity and Ca/P ratio. The prepared CHN/GLN scaffolds displayed highly porous architecture with elastic nature. The effect of increase in GLN content on osteoblast proliferation was evident but no significant impact on alkaline phosphatase (ALP) activity. When the CHN/GLN scaffold was coated with CaP film, ALP activity was dramatically improved, and the 75/25 scaffold showed the highest ALP level among all CHN/GLN scaffolds. The present study demonstrated that the combination of CHN, GLN, and CaP coating can generate synergistic effects on the improvement of bioactivity of CHN/GLN scaffold and can be further used for the fabrication of hard tissue scaffolds.

Multi-Functional Electrospun Nanofibers from Polymer Blends for Scaffold Tissue Engineering

Electrospinning and polymer blending have been the focus of research and the industry for their versatility, scalability, and potential applications across many different fields. In tissue engineering, nanofiber scaffolds composed of natural fibers, synthetic fibers, or a mixture of both have been reported. This review reports recent advances in polymer blended scaffolds for tissue engineering and the fabrication of functional scaffolds by electrospinning. A brief theory of electrospinning and the general setup as well as modifications used are presented. Polymer blends, including blends with natural polymers, synthetic polymers, mixture of natural and synthetic polymers, and nanofiller systems, are discussed in detail and reviewed.

Characterization of Chitosan-Gelatin Blend Scaffolds

Vacuum freeze-drying was used to prepare chitosan-gelatin (CG) scaffolds from hydrogels, with glutaraldehyde (GA) used as a crosslinker. The effects of the changes in volume ratios of the 2 wt% CG and GA solutions on scaffold performance were studied. The ratio of chitosan to gelatin solution volumes, vr(C/G), was adjusted to 1/2 or 1/1, with the 0.25 wt% GA volume at 3, 6, or 8% of the CG/GA volume. Six groups of CG scaffolds were fabricated and the scaffolds performance compared. After the cells were incubated for 4 days, hematoxylin eosin (HE) staining was used to observe the spreading of human skin keratinocyte (HaCaT) cells on these scaffolds, with the MTT method also used to detect the cells proliferation. The inhibition zone method was used on cells cultures to determine the antibacterial properties of the scaffolds against S. aureus and E. coli. Scaffolds were also examined for degradation in lysozyme and their compression properties were tested after degradation. The results showed that the HaCaT cells grew well on these scaffolds and proliferated significantly, indicating that these scaffolds possessed good cytocompatibility. With increased chitosan volume, the antibacterial properties of the scaffolds against S. aureus increased, however, there was no significant change in the antibacterial properties toward E. coli. Increased volumes of chitosan and GA decreased the scaffolds degradation rates and improved the elastic compressive moduli of the scaffolds after degradation. The scaffolds in the vr(C/G) = 1/1, 8% GA group have potential application prospects in the field of skin regeneration.

Development and Characterization of Sodium Alginate/Poly(vinyl alcohol) Blend Scaffold with Ciprofloxacin Loaded in Controlled Drug Delivery System.

Sodium Alginate/Poly(vinyl alcohol) (SA/PVA) blend scaffolds were successfully prepared via solution casting method for controlled release of ciprofloxacin (CPF). The structures of the films were evaluated by ATR-FTIR, XRD and SEM. A wide variety of material characteristics for the SA/PVA blend scaffolds were investigated, including the swelling behaviour, liquid displacement method, mechanical property and antibacterial activity. ATR-FTIR studies evaluated the chemical interaction between the biopolymeric scaffolds and the drug. XRD studies proved the amorphous behaviour of the prepared scaffolds. SEM images revealed good cohesivity and compatibility between the biopolymers and the cargos. SA/PVA loaded with ciprofloxacin showed maximum swelling percentage, porosity and tensile strength. The formulated ciprofloxacin loaded SA/PVA scaffold showed strong antibacterial activity. The results of CPF release from biopolymeric scaffolds at pH 1.2, 5.3 and 7.4 indicated strong pH dependence. In vitro drug-controlled release studies showed a slower and more continuous release for the SA/PVA in comparison with plain SA and PVA and the drug-delivery cumulative release was proportional to the amount and the interlayer distance of SA/PVA blend scaffolds. A sustained drug release pattern was observed with a non fickian diffusion mechanism.

Fabrication of Poly(L-Lactic Acid)/Chitosan Scaffolds by Solid-Liquid Phase Separation Method for Nerve Tissue Engineering: An In Vitro Study on Human Neuroblasts.

Polymeric scaffolds that support neural cell behaviors are attracting more attention. In the present study, solid-liquid phase separation technique is used to fabricate scaffolds made of poly(L-lactic acid) (PLLA) and chitosan (CS) blends to mimic both cellular microenvironment and anatomical structure of nerve tissue. The fabricated scaffolds favor characteristics of both natural and synthetic polymers. Different tests and assays including physical and mechanical ones (in vitro degradation rate, free radical release, hydrophilicity, and porosity measurements, microstructure observation, and mechanical tests) and cellular assays (cell attachment measurement and viability assessment) suggest that blend scaffolds prepared with this method support nerve cells for tissue engineering applications adequately and even better than scaffolds prepared with the same method but from pure PLLA or CS.

Cell growth and orientation of corneal stroma keratocytes on electrospun polycaprolactone-collagen scaffolds

Background & Aim Corneal cells, namely keratocytes, are a hallmark cell type for topical ocular drugs, eye drops, and drug toxicity studies. However, there has yet to exist in-vitro models of keratocytes mimicking natural corneal cells, which align in the direction of parallel collagen fibers in corneal stroma. By culturing cells on tissue-engineered scaffolds that closely mimic the structure of the stroma, cell growth and behavior should be improved. In this study, we investigated the effect of scaffold fiber orientation on the survivability and proliferation of corneal stroma keratocytes. Methods, Results & Conclusion Three different types of materials, polycaprolactone, polycaprolactone-jellyfish collagen blend, and polycaprolactone-bovine dermis atelocollagen blend, were electrospun to obtain nanofibrous scaffolds with both random and aligned fiber orientations. Keratocytes were cultured on the scaffolds over a duration of 4 days, and their survivability and cellular alignment was determined using a live and dead cell assay on day 1 and day 4. In addition, cell proliferation was measured using 4′,6-diamidino-2-phenylindole (DAPI) staining on day 1 and day 4. The results show that cells survive and proliferate better on the aligned fibers by 2-fold, with the orientation of cell growth matching that of the fibers, as shown in Fig. 1. Moreover, polycaprolactone-atelocollagen blended scaffolds favor cell survivability and proliferation as compared to pure polycaprolactone and polycaprolactone-jellyfish collagen scaffolds. Our polycaprolactone-atelocollagen scaffolds have potential applications in scaffold-based drug screening, drug toxicity testing and tissue-engineering for corneal regeneration. Corneal cells, namely keratocytes, are a hallmark cell type for topical ocular drugs, eye drops, and drug toxicity studies. However, there has yet to exist in-vitro models of keratocytes mimicking natural corneal cells, which align in the direction of parallel collagen fibers in corneal stroma. By culturing cells on tissue-engineered scaffolds that closely mimic the structure of the stroma, cell growth and behavior should be improved. In this study, we investigated the effect of scaffold fiber orientation on the survivability and proliferation of corneal stroma keratocytes. Three different types of materials, polycaprolactone, polycaprolactone-jellyfish collagen blend, and polycaprolactone-bovine dermis atelocollagen blend, were electrospun to obtain nanofibrous scaffolds with both random and aligned fiber orientations. Keratocytes were cultured on the scaffolds over a duration of 4 days, and their survivability and cellular alignment was determined using a live and dead cell assay on day 1 and day 4. In addition, cell proliferation was measured using 4′,6-diamidino-2-phenylindole (DAPI) staining on day 1 and day 4. The results show that cells survive and proliferate better on the aligned fibers by 2-fold, with the orientation of cell growth matching that of the fibers, as shown in Fig. 1. Moreover, polycaprolactone-atelocollagen blended scaffolds favor cell survivability and proliferation as compared to pure polycaprolactone and polycaprolactone-jellyfish collagen scaffolds. Our polycaprolactone-atelocollagen scaffolds have potential applications in scaffold-based drug screening, drug toxicity testing and tissue-engineering for corneal regeneration.

Biomimetic poly(glycerol sebacate)/polycaprolactone blend scaffolds for cartilage tissue engineering.

Poly (glycerol sebacate) (PGS) is a synthetic polymeric material with the characteristics of controllable degradation, high plasticity and excellent biocompatibility. However, the time of PGS degradation is faster than that of cartilage regeneration, which limits its application in cartilage tissue engineering. Polycaprolactone (PCL), a widely used synthetic polymer, has appropriate biodegradability and higher mechanical strength. This study aims to make a scaffold from blends of fast degrading PGS and slowly degrading PCL, and to investigate its potential for cartilage tissue engineering applications. Scanning electron microscopic analysis indicated that the scaffolds provided favourable porous microstructures. In vitro degradation test showed that PGS/ PCL scaffolds acquired longer degradation time and better mechanical strength. PGS/PCL scaffolds seeded with Bone marrow-derived mesenchymal stem cells (BMSCs) and articular chondrocytes (ACCs) were cultured in vitro. Short-term in vitro experiments confirmed that both seeded cells could adhere and proliferate on the scaffold. Chondrogenic culture for cell-scaffold constructs confirmed BMSCs could differentiate into chondrocyte-like cells in PGS/PCL scaffolds. With tunable biodegradation, favorable mechanical properties and cytocompatibility, PGS/PCL scaffolds would potentially be suitable for the regeneration of cartilage tissue. Poly (glycerol sebacate) (PGS) is a synthetic polymeric material with the characteristics of controllable degradation, high plasticity and good biocompatibility. However, the time of PGS degradation is faster than that of cartilage regeneration, which limits its application in cartilage tissue engineering. Polycaprolactone(PCL), a widely used synthetic polymer, has appropriate biodegradability. This study aims to make a scaffold from blends of fast degrading PGS and slowly degrading PCL, and to investigate its potential for cartilage tissue engineering applications. Scanning electron microscopic analysis indicated that the scaffolds provided favourable porous microstructures. In vitro degradation test showed that PGS/ PCL scaffolds got longer degradation time with surface degradation nature. PGS/PCL scaffolds seeded with Bone marrow-derived mesenchymal stem cells (BMSCs) and articular chondrocytes (ACCs) were cultured in vitro under the same condition. Short-term in vitro experiments confirmed that both seed cells could adhere and proliferate on the scaffold. Chondrogenic culture for cell-scaffold constructs confirmed BMSCs could differentiate into chondrocyte-like cells and form cartilage-specific matrix in PGS/PCL scaffolds. With cytocompatibility and biodegradation profile, PGS/PCL scaffolds get great potential for cartilage tissue engineering.